# My Dad's Favorite

Algebra Level 5

$\large f(x) = x^{150} + x^{149} + x^{148} + \cdots + x +1$

Let $x_{1}$, $x_{2}$ $\ldots$ $x_{150}$ be the roots of the equation $f(x) = 0$.

Then find the value of

$\ \sum_{1\leq i < j \leq 150} \dfrac{1}{(1-x_{i})(1-x_{j})}$

×