北师大版七年级数学下册同步练习 1.4 整式的乘法
一、单选题
1.计算(2x2-4)的结果,与下列哪一个式子相同 ( )
A.-x2+2 B.x3+4
C.x3-4x+4 D.x3-2x2-2x+4
2.计算:的结果是( )
A. B. C. D.
3.计算(-2ab)(3a2b2)3的结果是( )
A.-6a3b3 B.54a7b7 C.-6a7b7 D.-54a7b7
4.若(x+2)(x﹣1)=x2+mx+n,则m+n=( )
A.1 B.-2 C.-1 D.2
5.2a3·(b2-5ac)等于( )
A.-20a6b2c B.10a5b2c C.2a3b2-10a4c D.a7b4c -10a4c
6.一个长方体的长、宽、高分别是3x-4、2x-1和x,则它的体积是( )
A.6x3-5x2+4x B.6x3-11x2+4x
C.6x3-4x2 D.6x3-4x2+x+4
7.的结果是( )
A. B. C. D.
8.计算(-3xy2)·(2y2-xyz+1)的结果是( )
A.-3xy4+32y3+3xy2 B.-6xy4+3x2y3z-3xy2
C.-6xy4-3x2y3z-3xy2 D.-6xy4+3x2y2z
9.计算(2x-1)(5x+2)的结果是( )
A.10x2-2 B.10x2-5x-2 C.10x2+4x-2 D.10x2-x-2
10.(2x)2.[(-y2)2+z]等于( )
A.4xy4+xz B.-4x2y4+4x2z C.2x2y4+2x2z D.4x2y4+4x2z
二、填空题
11.计算:(1)(2x+3)(x-2)=__________;(2)(3a-2)(2a+5)=________________.
12.要使(x2+ax+1) (﹣6x3)的展开式中不含x4项,则a=___________.
13.在x+p与x2-2x+1的积中不含x,则p的值为_________.
14.已知m+n=mn,则(m-1)(n-1)=_______.
15.(-4x2)·(3x+1)等于_______.
三、解答题
16.计算:
(1)x(x+3)(x+5);
(2)(5x+2y)(5x-2y)-5x(5x-3y)
17.若,求的值.
18.已知多项式M=x2+5x-a,N=-x+2,P=x3+3x2+5,且M·N+P的值与x的取值无关,求字母a的值.
19.化简求值:
(5x﹣y)(y+2x)﹣(3y+2x)(3y﹣x),其中x=1,y=2
参考答案:
1.D
2.C
3.D
4.C
5.C
6.B
7.A
8.B
9.D
10.D
11. 2x2-x-6 6a2+11a-10
12.0
13.
14.1
15.-12x3-4x2
16.(1) x3+8x2+15x;(2)-4y2+15xy
17..
18.-10
19.12x2-10y2,-28