# How do you solve 4b^2+2=326?

Mar 16, 2018

$b = \pm 9$

#### Explanation:

$\text{subtract 2 from both sides of the equation}$

$\Rightarrow 4 {b}^{2} = 324$

$\text{divide both sides by 4}$

$\Rightarrow {b}^{2} = 81$

$\textcolor{b l u e}{\text{take the square root of both sides}}$

$\Rightarrow b = \pm \sqrt{81} \leftarrow \textcolor{b l u e}{\text{note plus or minus}}$

$\Rightarrow b = \pm 9$

Mar 16, 2018

$b = \pm 9$

#### Explanation:

As with any equation, we want to get the unknown value we are trying to work out on its own. Therefore we need to get rid of the $+ 2$, and by doing this we do the opposite to both sides, which is to $- 2$:

$4 {b}^{2} + 2 = 326 \to 4 {b}^{2} = 324$

As we would like to have B on its own, we need to get rid of the $4$ in front, and by doing this we do the opposite to both sides, which is to $/ 4$

$4 {b}^{2} = 324 \to {b}^{2} = 81$

Now we want b on its own again, we do not want the $^ 2$ added on, therefore, we do the opposite which is to sqrt:

${b}^{2} = 81 \to b = \pm \sqrt{81}$

$\to b = \pm 9$

Always remember the $\pm$, and this is our final answer as it cannot be simplified further.