# How do you solve  4sqrtx – 7 = 13?

Mar 11, 2018

$x = 25$

#### Explanation:

Add $7$ to both sides:

$4 \sqrt{x} - \cancel{7 + 7} = 13 + 7$

$4 \sqrt{x} = 20$

Divide both sides by $4$:

$\frac{\cancel{4} \sqrt{x}}{\cancel{4}} = \frac{20}{4}$

$\sqrt{x} = 5$

Square both sides:

${\left(\sqrt{x}\right)}^{2} = {5}^{2}$

$x = 25$

Mar 11, 2018

See a solution process below:

#### Explanation:

First, add $\textcolor{red}{7}$ to each side of the equation to isolate the $x$ term while keeping the equation balanced:

$4 \sqrt{x} - 7 + \textcolor{red}{7} = 13 + \textcolor{red}{7}$

$4 \sqrt{x} - 0 = 20$

$4 \sqrt{x} = 20$

Next, divide each side of the equation by $\textcolor{red}{4}$ to isolate the radical while keeping the equation balanced:

$\frac{4 \sqrt{x}}{\textcolor{red}{4}} = \frac{20}{\textcolor{red}{4}}$

$\frac{\textcolor{red}{\cancel{\textcolor{b l a c k}{4}}} \sqrt{x}}{\cancel{\textcolor{red}{4}}} = 5$

$\sqrt{x} = 5$

Now, square both sides of the equation to solve for $x$ while keeping the equation balanced:

${\left(\sqrt{x}\right)}^{2} = {5}^{2}$

$x = 25$