化简求值(x平方+3x)(x-3)-x(x-2)平方+(-x-y)(y-x),其中x=3,y=-2,要狠详细的过程

2025-05-20 05:52:08
推荐回答(1个)
回答1:

=x(x+3)(x-3)-x(x-2)²+(x+y)(x-y)
=x(x²-9)-x(x²-4x+4)+(x²-y²)
=5x²-13x-y²
=45-39-4
=2