# How do you solve  -9x^2 + 18x + 27 = 0?

Jul 17, 2016

$x = 3 \mathmr{and} x = - 1$

#### Explanation:

Divide through by -9 first. This will make the ${x}^{2}$ term positive, and change the equation into its simplest form.

${x}^{2} - 2 x - 3 = 0$

Find factors of 3 which will subtract to make 2.
Signs will be different with more negatives.

The factors are 3 and 1, but we need -3 and +1.

$\left(x - 3\right) \left(x + 1\right) = 0$

One of the factors must be equal to 0.

If $x - 3 = 0 \text{ } x = 3$

If $x + 1 = 0 \text{ } x = - 1$