写出等式中未知的分母：(x-y)/(5-y)=(y-x)^2/( )
问题描述：
写出等式中未知的分母：(x-y)/(5-y)=(y-x)^2/( )
答
(x-y)/(5-y)=(y-x)^2/( )
等式中未知的分母
应等于
[(y-x)^2]/[(x-y)/(5-y)]
=[(x-y)(x-y)(5-y)][(x-y)]
=(x-y)(5-y)
=y^2-xy-5y+5x