Median-of-Medians proof for time complexity


Wikipedia mentions, that from the formula $ $ T(n) \leq T(n/5) + T(n\cdot7/10) + c \cdot n $ $

one can “easily” show using induction that

$ $ T(n) \leq 10 \cdot c \cdot n $ $

I am, as it seems, not so smart. So, can anyone tell me how to show this using induction?