When you want to solve an equation with containing a radical
expression you have to isolate the radical on one side from all
other terms and then square both sides of the equation.
When you square a radical equation you sometimes get a solution
to the squared equation that is not a solution to the original
equation. Such an equation is called an extraneous solution.
Remember to always check your solutions in the original equation to
discard the extraneous solutions.
Here we've got two solutions x = 1 or x = (-2). We check both
solutions in the original equation to test whether they are true
solutions or extraneous solutions.
As we could see when we checked our numbers in the original
equation x =1 is the only true solution for this equation and that
x = -2 is an extraneous solution.
Video lesson: Solve the radical equation