Question

试说明代数式[(x-y)^2-(x+y)(x-y)]除(-2y)+y的值与y的值无关

Answer 1

[(x-y)^2-(x+y)(x-y)]除(-2y)+y

=(x²-2xy+y²-x²+y²)÷(-2y)+y

=(2y²-2xy)÷(-2y)+y

=-y+x+y

=x

∴结果与y的值无关