= { 1+2y(y-x)/(x-y)(x+y)}/{(x-y+2y)/(x-y)}

= {(x+y-2y)/(x+y)}/{(x+y)/(x-y)}

={(x-y)/(x+y)}*(x-y)/(x+y)

=(x-y)^2/(x+y)^2

It is known that 3x+2y=0.

Y=-3x/2 substitution

(x+3x/2)^2/(x-3x/2)^2

=(5x/2)^2/(-x/2)^2

=25