(1)4x(a+b)-3x²(a+b);

题目

(1)4x(a+b)-3x²(a+b);
(2)a(x-2y)-b(2y-x)-c(x-2y);
(3)15a²(x-y)-5a(y-x);
(4)(3x+y)(3x-y)-(x+3y)(y-3x);

答案

(1)4x(a+b)-3x²(a+b); =x(a+b)(4-3x)(2)a(x-2y)-b(2y-x)-c(x-2y); =a(x-2y)+b(x-2y)-c(x-2y); =(a+b-c)(x-2y)(3)15a²(x-y)-5a(y-x); =15a²(x-y)+5a(x-y)=5a(x-y)(3a+1)(4)(3x+y)(3x-y)-(x+3y)(y-3x);...