来自景亮的问题
【(a-b)(a^2+b^2)(a+b)[(x-y)^2-(x-y)(x+y)]/(2y)】
(a-b)(a^2+b^2)(a+b)
[(x-y)^2-(x-y)(x+y)]/(2y)
1回答
2020-01-26 18:30
【(a-b)(a^2+b^2)(a+b)[(x-y)^2-(x-y)(x+y)]/(2y)】
(a-b)(a^2+b^2)(a+b)
[(x-y)^2-(x-y)(x+y)]/(2y)
(a-b)(a^2+b^2)(a+b)=(a^2+b^2)[(a+b)(a-b)]=(a^2+b^2)(a^2-b^2)=a^4-b^4[(x-y)^2-(x-y)(x+y)]/(2y)=(x^2-2xy+y^2-x^2+y^2)/(2y)=(-2xy+2y^2)/(2y)=2y(-x+y)/(2y)=-x+y