Answer
$x= -3 ± 3\sqrt 2$
Work Step by Step
The trinomial cannot be factored so we use the quadratic formula to calculate the x.
$x= \frac{-b ± \sqrt (b^{2} - 4ac)}{2a}$
$x^{2} + 6x -9$
In this trinomial a = 1, b= 6 and c= -9
$x= \frac{-(6) ± \sqrt (6^{2} - 4(1)(-9))}{2(1)}$
$x= \frac{-6 ± \sqrt (36 + 36)}{2}$
$x= \frac{-6 ± \sqrt (72)}{2}$
Square root of 72 is $6\sqrt 2$ because the factors of 72 are 36 and 2 and 36 is a perfect square of 6.
$x= \frac{-6 ± 6\sqrt 2}{2}$
We simplify the numbers to get the final x value.
$x= -3 ± 3\sqrt 2$
