Question

还有几道题要麻烦你（要过程）1.（x-y)的平方*（x+y）+（x+y）的平方*（y-x）2.x的平方-20xy-150

Answer 1

1、

原式=(x-y)²(x+y)-(x+y)²(x-y)

=(x+y)(x-y)(x-y-x-y)

=-2y(x+y)(x-y)

2、

原式=x²-50xy+30xy-1500y²

=x(x-50y)+30y(x-50y)

=(x-50y)(x+30y)

3、

原式=(a-b)²-3(a-b)-4

=(a-b-4)(a-b+1)