Solving an Equation That Contains a Square Root
An equation with a variable in a radicand is called a radical equation.
Here are three examples:
The following procedure may be used to solve an equation that contains a
variable under a square root symbol.
Procedure — To Solve an Equation That Contains a Variable
Under a Square Root Symbol
Step 1 Isolate the square-root radical on one side of the equation.
Step 2 Square both sides of the equation.
Step 3 Solve for the variable.
Step 4 Check the answer.
Example 1
Solve:
Solution
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Step 1 Isolate the square-root radical
on one side of the equation.
Add 3 to both sides of the equation.
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Step 2 Square both sides of the equation.
Simplify.
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Step 3 Solve for the variable.
Divide both sides by 2.
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x = 5 |
Step 4 Check the answer.
To check, substitute 50 for x in the original
equation and simplify. |
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So, x = 50 is the solution of the radical equation.
Example 2
Solve:
Solution
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Step 1 Isolate the square-root radical
on one side of the equation.
Subtract 4 from both sides of the equation.
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Step 2 Square both sides of the equation.
Simplify.
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Step 3 Solve for the variable.
Add 5 to both sides of the equation.
Divide both sides by 2.
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2x = 54 x = 27 |
Step 4 Check the answer.
To check, substitute 27 for x in the original
equation and simplify. |
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So, x = 27 is the solution of the radical equation.
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