上海教育版数学七年级上册9.16《分组分解法》练习题

9.16分组分解法

「、课本巩固练习

i?将下列各式分解因式

(1) x223x 60 (2) x2「xy_56y2

2

(3) -1 y 20y (4) x x-2 -3

(6) x2 -4x $ -2 x2 -4x -15

2

(5) -x y 8xy -15y

2.若a, b, c是三角形三边的长，则代数式a2+b2—c2—2ab的值()

A ?大于零

B ?小于零

C ?大于或等于零

D ?小于或等于零

、基础过关

1:

⑵ 5x3 _15x? 一x 3

⑶ 7x2 -3y xy _21x

⑷ x(x —1)(x -2) -6

⑸ ab(x21) x(a2 b2)

⑹ 2bm「15bn 4am「30an

⑺ a2 _3a _ab 3b

⑻ a 2b _3a2 _6ab

⑼ 6x2 -15ab -10ax 9bx

⑽ 2x2 _3x _6xy 9y

2:

⑴ c - abed ac2 - bd

⑵ a5 a4 a3 2a2 2a 2

(3) (x-2y)(x-3y) (x-4y)(x-5y) (x-3y)(x-5y) (x-2y)(x-4y)

⑷ ax5 - ax4 ax - a

(5) ax「ay a2 bx「by ab

3:

(1)x2 _x _9y2 -3y

(2)x2 _y2 _z2 _2yz

(3)x3 x2y _ xy2 _ y3

(4)a2 -6ab 12b 9b2 -4a

2 2

(5)ax -bx bx _ ax a _ b

(6)x2 6xy 9y2 -16a2 8a -1

(7)a2-4ab 4b2-2a 4

(8)a2 b2 _c2 _4d2? 2ab 4cd

(9)x2 _3x 6xy 9y2 _9y

2 2 2

(10)x 4y 9z -4xy -12yz 6xz 4:

1. x4+x3 +4x2 +3x +3

4. x464

5:

1. a' -4a 3

2 x42x36x24x 8

3 a42a32a22a 1

3、a4a2b2 b4

3. x3 6x2 11x 6

6:

1. ab(c2 d2) cd(a2 b2)

2. ab(c d)(c-d) cd(a b)(a-b)

3. 3(ab cd) -(bc 9ad)

4. 1 _xy(1 _xy) _x3y3