求详细说明以下式子4x²/（x-y)(x-z）+4y²/（y-z)(y-x)+4z²/(z-x)(z-y)上式怎么转变成下式的呢4x²(y-z)-4y²(x-z)+4z²(x-y)/(x-y)(x-z)(y-z)

Question

求详细说明以下式子
4x²/（x-y)(x-z）+4y²/（y-z)(y-x)+4z²/(z-x)(z-y)
上式怎么转变成下式的呢
4x²(y-z)-4y²(x-z)+4z²(x-y)/(x-y)(x-z)(y-z)

Answer 1

4x²/（x-y)(x-z）+4y²/（y-z)(y-x)+4z²/(z-x)(z-y)
=4x²(y-z)/(x-y)(x-z)(y-z)-4y²(x-z)/(x-y)(x-z)(y-z)+4z²(x-y)/(x-y)(x-z)(y-z)
=[4x²(y-z)-4y²(x-z)+4z²(x-y)]/(x-y)(x-z)(y-z)