Prove an assertion for a measure $\mu$ with $\mu (A+h)=\mu (A)$

Question

I need to prove the following: Let $\mu:\mathscr{B}(\mathbb{R}) \to [0, \infty] $ (with $\mathscr{B}$ the Borel-sigma algebra on $\mathbb{R}$)be a measure such that for all $h \in \mathbb{R}$ and $A \in \mathscr{B}(\mathbb{R})$, $\mu$ with $\mu (A+h)=\mu (A)$. Prove that for each $x\geqslant 0$ and $q \in \mathbb{N}$, $\mu((0,qx])=q\mu((0,x])$. I think it is not really hard but I just don't know how to start because you don't know much about the measure. Can someone please help me?