Let $\displaystyle f,g:R\rightarrow R$ be Lebesgue integrable functions on the real line R and let $\displaystyle h(x)=\int_R f(x-y)g(y)dy$, $\displaystyle x \in R$.

Show that $\displaystyle f(x-y)g(y)$ is measurable on R.

i dont even know how to start. help is appreciated so much.