化简求值:(x^2-y^2)/x乘以2x/(x^2-2xy+y^2),其中x=2,y=1

问题描述:

化简求值:(x^2-y^2)/x乘以2x/(x^2-2xy+y^2),其中x=2,y=1

=(x+y)(x-y)/x×2x/(x-y)²
=(x+y)×2/(x-y)
=2(x+y)/(x-y)
=6