Question

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

Answer 1

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