# How do you solve X^2 + 100 = 20X?

Jun 14, 2016

First we get everything on the same side by subtracting $20 x$ on both sides.

#### Explanation:

${x}^{2} - 20 x + 100 = 0 \to$

Then we factor $100$ into two factors that add up to $- 20$,
those can only be $- 10 \mathmr{and} - 10$, so the whole left part can be factored:

$\left(x - 10\right) \left(x - 10\right) = 0 \to x - 10 = 0 \to x = 10$