Question

comedy数学题目额化简：（x^4-y^4）/（2x^2+xy-y^2）×（2x-y）/（xy-y^2）÷(x^2+y

Answer 1

原式=[(x²+y²)(x+y)(x-y)/(2x-y)(x+y)]×[(2x-y)/y(x-y)]÷[(x²+y²)²/4]

=[(x²+y²)(x-y)/(2x-y)]×[(2x-y)/y(x-y)]×[4/(x²+y²)²]

=4(x²+y²)(x-y)(2x-y)/[(2x-y)y(x-y)(x²+y²)²]

=4/[y(x²+y²)]