习题4.3第1题答案
(1)7(a-1)+x(a-1)=(a-1)(7+x)(2)3(a-b)2+6(b-a)=3(a-b)2-6(a-b)=3(a-b)(a-b-2)(3)2(m-n)2-m(m-n)=(m-n)[2(m-n)-m]=(m-n)(m-2n)(4)x(x-y)2-y(y-x)2=x(x-y)2-y(x-y)2=(x-y)2(x-y)=(x-y)3(5)m(a2+b2)+n(a2+b2)=(a2+b2)(m+n)(6)18(a-b)3-12b(b-a)2=18(a-b)3-12b(a-b)2=6(a-b)2[3(a-b)-2b]=6(a-b)2(3a-5b)(7)(2a+b)(2a-3b)-3a(2a+b)=(2a+b)(2a-3b-3a)=(2a+b)(-3b-a)=-(2a+b)(a+3b)(8)x(x+y)(x-y)-x(x+y)2=x(x+y)(x-y- x-y)=x(x+y)(-2y)=-2xy(x+y)习题4.3第2题答案
(1)4x(m-2)-3x(m-2)=  |