# How do you solve the equation 3(x^2+2)=18?

Mar 20, 2018

$2$

#### Explanation:

${x}^{2} + 2 = \frac{18}{3}$

${x}^{2} + 2 = 6$

${x}^{2} = 6 - 2$

${x}^{2} = 4$

$x = \sqrt{4}$

$x = 2$

Mar 29, 2018

$x = \pm 2$

#### Explanation:

Given   $3 \left({x}^{2} + 2\right) = 18$    Solve for $x$

1) Divide both sides by $3$
After you divide, you will get this:
${x}^{2} + 2 = 6$

2) Subtract $2$ from both sides to isolate the ${x}^{2}$ term
${x}^{2} = 4$

3) Find the square roots of both sides
$x = \pm 2$

. . . . . . . . Check . . . . . . .

Using the original equation, sub in either $+ 2$ or $- 2$ in the place of $x$. The equation should still equal $18$

$3 \left({x}^{2} + 2\right) = 18$

1) Sub in $- 2$

$3 \left({\left(- 2\right)}^{2} + 2\right)$ should still equal $18$

2)Square the $- 2$
3 (4+2) should still equal $18$

$3 \left(6\right)$ should still equal $18$
4) Clear the parentheses by distributing the $3$
18  "does equal"  18
$C h e c k$