(1) x/(x²+2xy+y²)=x/(x+y)²
y/(x+y)=y(x+y)/(x+y)²
(2) (x+4)/(x²+4x)=(x+4)/x(x+4)=1/x=(x-2)/x(x-2)
(x-5)/[x(x-5)-2(x-5)]=(x-5)/[(x-5)(x-2)]=1/(x-2)=x/x(x-2)