1、1.(-5a2b)(-3a)等于( )A15a3b B-15a2b C-15a3b D-8a2b2.(2a)3(-5b2)等于( )A10a3b B-40a3b2 C-40a3b D-40a2b3.(2a3b)2(-5ab2c)等于( )A-20a6b4c B10a7b4c C-20a7b4c D20a7b4c 4.(2x3y)2(5xy2)x7 等于( )A-20x6y4 B10xyy4 C-20x7y4 D20x14y45下列计算正确的是 ( )A9a32 a218 a5 B2 x53 x45 x9C3 x34 x312 x3 D3 y35 y315 y96下列计算错误的是 ( )A(-2
2、.4 x2 y3)(0.5 x4)-1.2 x6 y3 B(-8 a3bc)= a4 b2cxC(-2 an) 2(3 a2)3-54 a2n+6 Dx2n+2(-3 xn+2)=-3x3n+47(-x5) 2(-x5x2) 2 8(xn) 2+5 xn-2xn+2 9= .10(4103) 3(-0. 125102) 2 11(0.1ab3)(0.3a3bc) 12a3 x3(-2 ax2) 13xy =-x y2z.14计算(1)(-3 an+2b) 3(-4abn+3)2;(2)(-7 a2 xn)(-3 ax2)(- am xn)(m0,n0);(3)(-10x2y)(2xy4z)(4)(-2 x y2)(-3 x2y4)(- x y)答案:1.A 2.B 3.C 4.D 5A 6C7x24 86x2n 94 x14 101013 110.03 a4 b4 c 12-2 a3 x5 13- yz 14解:(1)-432 a3n+8 b2n+9 (2)-2l am+3 x2n+2(3)-20 x3 y5 z(4)(-2 x y2)(-3 x2y4)(- x y)= -6 x1+2+1y2+4+1=-6 x4 y7