问题 选择题

下列各题中,分解因式正确的是(  )

A.b(a-4)-c(4-a)=(a-4)(b-c)

B.x2(x-2)2+2x(x-2)2=(x-2)2(x2+2x)

C.(a-b)(a-c)+(b-a)(b-c)=(a-b)(a+b-2c)

D.5a(x-y)+10b(y-x)=5(x-y)(a-2b)

答案

A、应为b(a-4)-c(4-a),

=b(a-4)+c(a-4),

=(a-4)(b+c),故本选项错误

B、应为x2(x-2)2+2x(x-2)2

=x(x-2)2(x+2),故本选项错误;

C、应为(a-b)(a-c)+(b-a)(b-c),

=(a-b)(a-c-b+c),

=(a-b)2,故本选项错误;

D、5a(x-y)+10b(y-x),

=5(x-y)(a-2b),正确.

故选D.

探究题
单项选择题