# The Degree Isn't Given Either?

Algebra Level 5

Let $$a_1, a_2, \ldots , a_n$$ be the roots of the equation $$\displaystyle \sum_{k=1}^n kx^k = 0$$. If $$\displaystyle \sum_{k=1}^n \dfrac1{1-a_k} = 7$$, find $$n$$.

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