Use the indenities; $\displaystyle (sinA+sinB) $ and $\displaystyle (cosA+cosB) $

to prove that $\displaystyle \frac{sin2x+sin2y}{cos2x+cos2y} = tan(x+y) $

I am really stuck on this, as the question is not clear to me. Is it talking about the addition formula? sin(A+B).