Radicals and radical equations
Simplify by pulling out the largest perfect square. Undo a square root by squaring both sides.
A worked example
√50 = √25 x √2 = 5√2. To solve √(3x + 1) = 4, square both sides: 3x + 1 = 16, so x = 5.
The mistake people actually make
Squaring can create extraneous roots, so always substitute your answer back into the original equation.