Question

1.已知x-y=2,x²-y²=10,则-x-y 2.（a+b）的3次方（a-b）的平方除以（a

Answer 1

1.x-y=2,①

x²-y²=10,②

②/①,x+y=5,

∴-x-y=-(x+y)=-5.

2.（a+b）^3*（a-b）^2÷（a²-b²）²

=(a+b)^3*(a-b)^2÷[(a+b)^2*(a-b)^2]

=a+b.