Question

3(x-y)2方-7（x+y)+8（x-y）2方+6（x+y).

Answer 1

3(x-y)2方-7（x+y)+8（x-y）2方+6（x+y)

=3(x-y)2方+8（x-y）2方-7（x+y)+6（x+y)

=11(x-y)2方-（x-y）

=11(x2-2xy+y2方)-x-y

=11x2方-22xy+11y2方-x-y