Question

1.把(x减y)看做一个整体,则3(x减y)的平方减去(x减去y)的立方加上7(x减去y)的平方加上4(x减去y)的三次

Answer 1

3(x-y)²-(x-y)³+7(x-y)²+4(x-y)³

=(3+7)(x-y)²+(4-1)(x-y)³

=10(x-y)²+3(x-y)³