## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$x=\dfrac{9}{2}$
Using the properties of equality, the given equation, $\sqrt{2x}-1=2$, is equivalent to \begin{array}{l} \sqrt{2x}=2+1 \\\\ \sqrt{2x}=3 .\end{array} Raising both sides to the $\text{ 2nd }$ power, the solution to the equation above, $\sqrt{2x}=3$, is \begin{array}{l} 2x=9 \\\\ x=\dfrac{9}{2} .\end{array} Upon checking, $x=\dfrac{9}{2}$ satisfies the given equation.