若y-2x=0,则分式(x^2+xy+y^2)/(x^2-xy+2y^2)=_数学解答

若y-2x=0,则分式(x^2+xy+y^2)/(x^2-xy+2y^2)=

人气：377 ℃　时间：2019-08-22 08:08:56

解答

y-2x=0,y=2x
(x^2+xy+y^2)/(x^2-xy+2y^2)
=(x^2+3x^2+4x^2)/(x^2-3x^2+4x^2)
=7x^2/2x^2
=7/2