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

Question

2087 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-17T16:43:40

$x = 3 or x = -1$

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

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

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.

$(x-3)(x+1) = 0$

One of the factors must be equal to 0.

If $x-3 = 0 " " x = 3$

If $x+1 = 0 " " x = -1$

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