Algebra Examples
2x2−4x−16=0
Step 1
Add 16 to both sides of the equation.
2x2−4x=16
Step 2
Step 2.1
Divide each term in 2x2−4x=16 by 2.
2x22+−4x2=162
Step 2.2
Simplify the left side.
Step 2.2.1
Simplify each term.
Step 2.2.1.1
Cancel the common factor of 2.
Step 2.2.1.1.1
Cancel the common factor.
2x22+−4x2=162
Step 2.2.1.1.2
Divide x2 by 1.
x2+−4x2=162
x2+−4x2=162
Step 2.2.1.2
Cancel the common factor of −4 and 2.
Step 2.2.1.2.1
Factor 2 out of −4x.
x2+2(−2x)2=162
Step 2.2.1.2.2
Cancel the common factors.
Step 2.2.1.2.2.1
Factor 2 out of 2.
x2+2(−2x)2(1)=162
Step 2.2.1.2.2.2
Cancel the common factor.
x2+2(−2x)2⋅1=162
Step 2.2.1.2.2.3
Rewrite the expression.
x2+−2x1=162
Step 2.2.1.2.2.4
Divide −2x by 1.
x2−2x=162
x2−2x=162
x2−2x=162
x2−2x=162
x2−2x=162
Step 2.3
Simplify the right side.
Step 2.3.1
Divide 16 by 2.
x2−2x=8
x2−2x=8
x2−2x=8
Step 3
To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of b.
(b2)2=(−1)2
Step 4
Add the term to each side of the equation.
x2−2x+(−1)2=8+(−1)2
Step 5
Step 5.1
Simplify the left side.
Step 5.1.1
Raise −1 to the power of 2.
x2−2x+1=8+(−1)2
x2−2x+1=8+(−1)2
Step 5.2
Simplify the right side.
Step 5.2.1
Simplify 8+(−1)2.
Step 5.2.1.1
Raise −1 to the power of 2.
x2−2x+1=8+1
Step 5.2.1.2
Add 8 and 1.
x2−2x+1=9
x2−2x+1=9
x2−2x+1=9
x2−2x+1=9
Step 6
Factor the perfect trinomial square into (x−1)2.
(x−1)2=9
Step 7
Step 7.1
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
x−1=±√9
Step 7.2
Simplify ±√9.
Step 7.2.1
Rewrite 9 as 32.
x−1=±√32
Step 7.2.2
Pull terms out from under the radical, assuming positive real numbers.
x−1=±3
x−1=±3
Step 7.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 7.3.1
First, use the positive value of the ± to find the first solution.
x−1=3
Step 7.3.2
Move all terms not containing x to the right side of the equation.
Step 7.3.2.1
Add 1 to both sides of the equation.
x=3+1
Step 7.3.2.2
Add 3 and 1.
x=4
x=4
Step 7.3.3
Next, use the negative value of the ± to find the second solution.
x−1=−3
Step 7.3.4
Move all terms not containing x to the right side of the equation.
Step 7.3.4.1
Add 1 to both sides of the equation.
x=−3+1
Step 7.3.4.2
Add −3 and 1.
x=−2
x=−2
Step 7.3.5
The complete solution is the result of both the positive and negative portions of the solution.
x=4,−2
x=4,−2
x=4,−2