How do you solve 3x^2+45=24x by factoring?

Oct 26, 2016

$x = 5$, $3$

Explanation:

$3 {x}^{2} + 45 = 24 x$

$3 {x}^{2} - 24 x + 45 = 0$

Factorise.

$3 {x}^{2} - 9 x - 15 x + 45 = 0$

$3 x \left(x - 3\right) - 15 \left(x - 3\right) = 0$

$\left(3 x - 15\right) \left(x - 3\right) = 0$

$3 x - 15 = 0$ and $x - 3 = 0$

$\therefore x = \frac{15}{3} = 5$ and $x = 3$