(x+4)/(x^2+2x)-1/(x+2)=2/x
(x+4)/(x(x+2))-x/(x(x+2))=2/x
(x+4-x)/(x(x+2))=2/x
4/(x(x+2))=2/x
2/(x+2)=1
x+2=2
x=4