# How do you solve x^2-15x+54=0?

Jan 16, 2017

$x = 6$ or $x = 9$

#### Explanation:

${x}^{2} - 15 x + 54 = 0$

Factorise.

${x}^{2} - 9 x - 6 x + 54 = 0$

$x \left(x - 9\right) - 6 \left(x - 9\right) = 0$

$\left(x - 6\right) \left(x - 9\right) = 0$

$x - 6 = 0$ or $x - 9 = 0$

$x = 6$ or $x = 9$