# How do you solve 4x^2 -18=82 graphically and algebraically?

Sep 11, 2017

By arranging the original equation

#### Explanation:

Your equation can be written
$4 {x}^{2} = 82 + 18$

$4 {x}^{2} = 100$

${x}^{2} = \frac{100}{4}$

${x}^{2} = 25$

The solution for x is $x = 5$ and $x = - 5$ (there are two values).

Graphically the solution is provided below

$y = {x}^{2} - 25$
When y is zero, you can find x (-5 and +5)

graph{(x^2)-25 [-10, 10, -30, 20]}