Question

Given that f(x) = 9x2 − 180, find x

Answer 1

-162
Because 9 x 2 = 18
18 - 180 = -162

Answer 2

Answer:

The values of x are $x=\sqrt{20},\:x=-\sqrt{20}$.

Step-by-step explanation:

We have the function $f(x) = 9x^{2} - 180$.

To find the value of x, you must set the function to zero

$9x^2\:-\:180=0$

Next, add 180 to both sides

$9x^2-180+180=0+180$

Simplify

$9x^2=180$

Divide both sides by 9

$\frac{9x^2}{9}=\frac{180}{9}$

Simplify

$x^2=20$

$\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}$

$x=\sqrt{20},\:x=-\sqrt{20}$.