KIEM TRA CHUONG I DAI SO 8

<span class='text_page_counter'>(1)</span>TRƯỜNG THCS NGUYỄN TRƯỜNG TỘ. Hä vµ tªn: ................................................ Líp: 8B §iÓm. Thø 2 ngµy 9 th¸ng 11 n¨m 2015 kiÓm tra Ch¬ng I : TiÕt 21 M«n: §¹i sè – (thêi gian: 45’) NhËn xÐt cña thÇy gi¸o. Bµi lµm: C©u 1: (1,5đ) Thùc hiÖn phÐp tÝnh : a , 5x(2x2 - 7x +5) ……………………………………………………………………………………………............. ........................................................................................................................................................ b , (x2 + 4x -1)(2x - 1) …………………………………………………………………………………………………… ……………………………………………………………………………..................................... C©u 2: (1,5) T×m x , biÕt : a) x2 - 9 = 0 .... …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………b) x2 + 6x +8 = 0 …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………………..................................... ........................................................................................................................................................ Câu 3: (1đ)Tìm aZ để : 4a2 + 6a - 1 chia hÕt cho 2a - 1 …………………………………………………………………………………………………… …………………………………………………………………………………............................. ......................................................................................................................................................... ......................................................................................................................................................... ......................................................................................................................................................... ......................................................................................................................................................... ......................................................................................................................................................... ……………………………………………………………………………………………………. C©u 4: (2®) §iÒn dÊu “X”vµo « thÝch hîp. C©u Néi dung §óng Sai 1 (x - 2)2 = x2 - 2x + 4 2 (x- y)2 = x2 - y2 3 - (x + 3)3 = (-x - 3)3 4 (x3 - 8) : (x - 2) = x2 + 2x + 4 C©u 5: (1,5®) Rót gän råi tÝnh gi¸ trÞ cña biÓu thøc sau t¹i x = 2; y = -3 M = 2(x - y)2 - 3(x + y)2 - (x - y)(x + y) + x(2x-5).

<span class='text_page_counter'>(2)</span> …………………………………………………………………………………………………… ……………………………………………………………………………………......................... ......................................................................................................................................................... …………………………………………………………………………………………................ C©u 6: ( 1,0®) Ph©n tÝch ®a thøc thµnh nh©n tö: a, x4-3x3-x+3 ……………………………………………………………………………………………............. ……………………………………………………………………………………………............. b, x2-10x+16 ……………………………………………………………………………………………............. ……………………………………………………………………………………………............. ......................................................................................................................................................... C©u 7:(0,5đ) . So s¸nh: A=1999.2001 vµ B=20002 …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………………..................................... C©u 8:(0,5đ) . CMR: (a + b)2 = (a - b)2 + 4ab …………………………………………………………………………………………………… …………………………………………………………………………………………………… …..................................................................................................................................................... ......................................................................................................................................................... C©u 9 : (0,5đ) .T×m gi¸ trÞ nhá nhÊt (Min) cña biÓu thøc . M = 2x2 - 4x -7 …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………………..................................... ......................................................................................................................................................... TR¦êNG THCS NGUYÔN TR¦êNG Té. Hä vµ tªn: ................................................ Líp: 8A §iÓm. Thø 2 ngµy 9 th¸ng 11 n¨m 2015 kiÓm tra Ch¬ng I : TiÕt 21 M«n: §¹i sè – (thêigian: 45’) NhËn xÐt cña thÇy gi¸o. Bµi lµm: C©u 1: (2,5) Thùc hiÖn phÐp tÝnh : a , 5x(2x2 - 7x +5) …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… b , (x2 + 4x -1)(2x - 1).

<span class='text_page_counter'>(3)</span> …………………………………………………………………………………………………… ……………………………………………………………………………..................................... ......................................................................................................................................................... ………………………………………………………………………………………………….... C©u 2:( 1,5) T×m x , biÕt . a) x2 - 9 = 0 .... …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………b) x2 + 6x +8 = 0 …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………………………………………. Câu 3: (1đ) Tìm aZ để : 4x2 + 6x + a - 1 chia hÕt cho 2x - 1 …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… ……………………………………………………………………................................................. ......................................................................................................................................................... ......................................................................................................................................................... ......................................................................................................................................................... ....................................................................................................................................................... C©u 4: (2 ®) §iÒn dÊu “X”vµo « thÝch hîp. C©u Néi dung §óng Sai 1 (x - 2)2 = x2 - 2x + 4 2 (x- y)2 = x2 - y2 3 - (x + 3)3 = (-x - 3)3 3 4 (x - 8) : (x - 2) = x2 + 2x + 4 C©u 5: (1,5®) Rót gän råi tÝnh gi¸ trÞ cña biÓu thøc sau t¹i x = 2; y = -3 M = 2(x - y)2 - 3(x + y)2 - (x - y)(x + y) + x(2x-5) …………………………………………………………………………………………………… ……………………………………………………………………………………………………. …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… …………………………………………………………………………………………………… C©u 6: ( 1®) Ph©n tÝch ®a thøc thµnh nh©n tö : x4-3x3-x+3 ……………………………………………………………………………………………………..

<span class='text_page_counter'>(4)</span> ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. C©u 7 : (0,5) T×m gi¸ trÞ nhá nhÊt (Min) cña biÓu thøc . M = 2x2 - 4x -7 ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. ……………………………………………………………………………………………………. …………………………………………………………………………………………………… …………………………………………………………………………………………………….

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