Let f: R → R be a function such that f(2-x)=f(2+x) and f(4-x)=f(4+x), for all x ∈ R and ∫_0^2 f(x) d x=5. Then the value of ∫_10^50 f(x) d x is:

Let $\displaystyle f: \mathbf{R} \rightarrow \mathbf{R}$ be a function such that $\displaystyle f(2-x)=f(2+x)$ and $\displaystyle f(4-x)=f(4+x)$, for all $\displaystyle x \in \mathbf{R}$ and $\displaystyle \int_0^2 f(x) \mathrm{d} x=5$. Then the value of $\displaystyle \int_{10}^{50} f(x) \mathrm{d} x$ is :