Precalculus Examples

Solve by Completing the Square x^2-4x-91=7
Step 1
Move all terms not containing to the right side of the equation.
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Step 1.1
Add to both sides of the equation.
Step 1.2
Add and .
Step 2
To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of .
Step 3
Add the term to each side of the equation.
Step 4
Simplify the equation.
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Step 4.1
Simplify the left side.
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Step 4.1.1
Raise to the power of .
Step 4.2
Simplify the right side.
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Step 4.2.1
Simplify .
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Step 4.2.1.1
Raise to the power of .
Step 4.2.1.2
Add and .
Step 5
Factor the perfect trinomial square into .
Step 6
Solve the equation for .
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Step 6.1
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 6.2
Add to both sides of the equation.
Step 7
The result can be shown in multiple forms.
Exact Form:
Decimal Form: