若3x-2y=0,则4x/x²-xy+y²=?
问题描述:
若3x-2y=0,则4x/x²-xy+y²=?
答
x=2/3y
4x/(x^2-xy+y^2)=8/3y/(4/9y^2-2/3y^2+y^2)=8/3y/(7/9y^2)=24/(7y)