SOLUTION: a convex n-gon has 5 times as many diagonals as sides. find the value of n

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Question 1000017: a convex n-gon has 5 times as many diagonals as sides. find the value of n
Answer by ikleyn(52818) About Me  (Show Source):
You can put this solution on YOUR website!
Your equation is 

%28n%2A%28n-3%29%29%2F2 = 5n.

Note that %28n%2A%28n-3%29%29%2F2 is the number of diagonal of a convex n-gon.

Simplify this equation:

n%5E2+-+3n = 10n,

n%5E2 = 13n.

The solution is n = 13.