De kiem tra dai so 8 chuong 2

<span class='text_page_counter'>(1)</span>Phòng GD & ĐT Lệ Thủy BÀI KIỂM TRA ĐẠI SỐ 8 Trường THCS Mai Thủy BÀI SỐ 2 Họ và tên:.......................................... Thời gian: 45 phút Lớp: .................................................. Điểm Lời nhận xét của giáo viên. ĐỀ SỐ I Câu 1 (3,0 điểm): Rút gọn các phân thức sau: 6x2 y2 5 a) 8 xy. 7 x 2  14 x  7 2 b) 3 x  3 x. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ................................................................................................................................................................................... Câu 2 (4,0 điểm): Thực hiện các phép tính sau: 13 y 3 y  5 xy 5 xy a). x  x  1.  x  1 x  1  x  1 b)  2. .. x 2  2 x  1 ( x  1)( x  3) : x2  4 c) 3x  6. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ...................................................................................................................................................................................

<span class='text_page_counter'>(2)</span>  x2  4   x  Câu 3 (3,0 điểm): Cho biểu thức P =.  x2 4. 3  x 2. a) Tìm điều kiện của x để giá trị của biểu thức P xác định. b) Rút gọn biểu thức P. c) Tính giá trị nhỏ nhất của P. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ...................................................................................................................................................................................

<span class='text_page_counter'>(3)</span> Phòng GD & ĐT Lệ Thủy BÀI KIỂM TRA ĐẠI SỐ 8 Trường THCS Mai Thủy BÀI SỐ 2 Họ và tên:.......................................... Thời gian: 45 phút Lớp: .................................................. Điểm Lời nhận xét của giáo viên. ĐỀ SỐ II Câu 1 (3,0 điểm): Rút gọn các phân thức sau: 12 x 3 y 2 5 a) 18 xy. 7 x 2  14 x  7 2 b) 3 x  3 x. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ................................................................................................................................................................................... Câu 2 (4,0 điểm): Thực hiện các phép tính sau: 16 y 2 y  7 xy 7 xy a). x  x  1.  x 1 x  1  x  1 b)  2. .. x 2  2 x  1 ( x  1)( x  3) : x2  4 c) 3 x  6. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ...................................................................................................................................................................................

<span class='text_page_counter'>(4)</span>  x2  4  x2  4 3  . x x2   Câu 3 (3,0 điểm): Cho biểu thức Q =. a) Tìm điều kiện của x để giá trị của biểu thức Q xác định. b) Rút gọn biểu thức Q. c) Tính giá trị nhỏ nhất của Q. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. .................................................................................................................................................................................. ...................................................................................................................................................................................

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