Answer
$\color{blue}{x=6}$
Work Step by Step
Add $\sqrt{3x+18}$ to both sides to obtain:
$x=\sqrt{3x+18}$
Square both sides to obtain:
$x^2=3x+18$
Move all terms to the left side of the equation.
Note that when a term is transferred to the other side of the equation, its sign changes to its opposite.
$x^2-3x-18=0$
Factor the trinomial to obtain:
$(x-6)(x+3)=0$
Use the zero-factor property by equating each factor to zero.
$x-6=0$ or $x+3=0$
Solve each equation to obtain:
$x=6$ or $x=-3$.
$-3$ cannot be a solution to the equation as $\sqrt{3x+18}$ is never negative.
Thus, the solution to the given equation is: $\color{blue}{x=6}$.
