How To solve radical expressions
 1) Isolate radical on one side of the equation
 2) Square both sides of the equation to eliminate radical
 3) Simplify and solve as you would any equations
 4) Substitute answers back into original equation to make sure that your solutions are valid (there could be some extraneous roots that do not satisfy the original equation and that you must throw out)
Video of How to Solve Radical Equations
Practice Problems
Isolate the radical
Square both sides
Solve expression
Substitute answer into original radical equation to verify that the answer is a real number
Isolate the radical
Square both sides
Solve expression
Substitute answer into original radical equation to verify that the answer is a real number
Isolate the radical
Square both sides
Solve expression
This quadratic equation can be solved by factoring
0 =(x 4)(x5)
x = 4, x = 5
Substitute answer into original radical equation to verify that the answer is a real number
Therefore, reject 4 as a solution, check 5
$$ \sqrt{3x 11} = 3x x \\ \sqrt{3 (\color{Red}{5}) 11} = 3(\color{Red}{5})  \color{Red}{5} \\ \sqrt{15 11} = 15  5 \\ \sqrt{15 11} = 15  5 \\ \sqrt{4} = 10 \\ 2 = 10 \\ \color{red}{ \ne } 10 $$Therefore, reject 5 as a solution
Since both our solutions were rejected, there are no real solutions to this equation.

Further Reading
 Radical Equations Worksheet 27 question pdf with answer key
 Radical Equations Solver