de kiem tra dai so 8 chuong 2

trờng t.h.c.s bài kiểm tra đại số 8
Hoằng Trinh Bài số: 2 Học kỳ I
Thời gian làm bài: 45 phút.

Họ và tên học sinh:.......................................Lớp:..........
Kiểm tra ngày.........tháng.........năm 2010
Điểm
Bằng số:......................
Bằng chữ:....................
Lời phê của thầy cô giáo
......................................................................................
......................................................................................
......................................................................................
Chữ ký GV kiểm tra:
Đề bài
I. Phn trc nghim : 3 im (Chn phng ỏn tr li ỳng)
Cõu 1: Kt qu rỳt gn phõn thc
3 2
6
14x y
21xy
l:
A.
3
3
2x
3y
B.
2
4
2x

3y
C.
2
3
D.
2 4
2x y
3y

Cõu 2: Kt qu rỳt gn phõn thc
2 2
2xy 10y
3xy 15y
+
+
l:
A.
2
3
B.
2
2xy
3xy
C.
2
2
3y
D.
2
3y

Cõu 3: Cho ng thc
3 2
x x ...
(x 1)(x 1) x 1
+
=
+
Hóy in a thc thớch hp vo ch .....
c mt ng thc ỳng
A. x
2
B. x C. x+1 D. x-1
Cõu 4: Mu thc chung ca cỏc phõn thc 2x v
1
3x 1+
l :
A. 2(3x+1) B. 3x+1 C. 2x D. 2x (3x+1)
Cõu 5: Kt qu phộp tớnh
2 5
4 3
25 34
.
17 15
x y
y x
l :
A.
10
3

x
y
B.
10
3
y
x
C. x D. 1
Cõu 6: Kt qu phộp tớnh :
3 15 5
:
2 2
x x
x x
+ +

l :
A. 1 B. -1 C. 3 D. -3
II. Phn t lun: (7 im )
Bi 7: Thc hin phộp cng cỏc phõn thc sau:
a,
2x 2
x 1 x 1
+
+ +
b,
2
2x 1 1 x
x 4 3x 6
+

+
+
Bi 8: Cho biu thc A=
2
2
5 6
9
x x
x
+ +

vi
3x

a) Rỳt gn biu thc A
b) Tỡm x, bit A = 2
c) Tỡm cỏc giỏ tr nguyờn ca x A nhn giỏ tr nguyờn.
Bµi lµm
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................

................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
.............................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
..............................................................................................................................
................................................................................................................................................
................................................................................................................................................
....................................................................................................................................... ........
.....................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................................
................................................................................................................................