Examples
f(x)=4x2+2f(x)=4x2+2 , f(x)=4x+1f(x)=4x+1
Step 1
Substitute 4x+14x+1 for f(x)f(x).
4x+1=4x2+24x+1=4x2+2
Step 2
Step 2.1
Subtract 4x24x2 from both sides of the equation.
4x+1-4x2=24x+1−4x2=2
Step 2.2
Subtract 22 from both sides of the equation.
4x+1-4x2-2=04x+1−4x2−2=0
Step 2.3
Subtract 22 from 11.
4x-4x2-1=04x−4x2−1=0
Step 2.4
Factor the left side of the equation.
Step 2.4.1
Factor -1−1 out of 4x-4x2-14x−4x2−1.
Step 2.4.1.1
Reorder 4x4x and -4x2−4x2.
-4x2+4x-1=0−4x2+4x−1=0
Step 2.4.1.2
Factor -1−1 out of -4x2−4x2.
-(4x2)+4x-1=0−(4x2)+4x−1=0
Step 2.4.1.3
Factor -1−1 out of 4x4x.
-(4x2)-(-4x)-1=0−(4x2)−(−4x)−1=0
Step 2.4.1.4
Rewrite -1−1 as -1(1)−1(1).
-(4x2)-(-4x)-1⋅1=0−(4x2)−(−4x)−1⋅1=0
Step 2.4.1.5
Factor -1−1 out of -(4x2)-(-4x)−(4x2)−(−4x).
-(4x2-4x)-1⋅1=0−(4x2−4x)−1⋅1=0
Step 2.4.1.6
Factor -1−1 out of -(4x2-4x)-1(1)−(4x2−4x)−1(1).
-(4x2-4x+1)=0−(4x2−4x+1)=0
-(4x2-4x+1)=0−(4x2−4x+1)=0
Step 2.4.2
Factor using the perfect square rule.
Step 2.4.2.1
Rewrite 4x24x2 as (2x)2(2x)2.
-((2x)2-4x+1)=0−((2x)2−4x+1)=0
Step 2.4.2.2
Rewrite 11 as 1212.
-((2x)2-4x+12)=0−((2x)2−4x+12)=0
Step 2.4.2.3
Check that the middle term is two times the product of the numbers being squared in the first term and third term.
4x=2⋅(2x)⋅14x=2⋅(2x)⋅1
Step 2.4.2.4
Rewrite the polynomial.
-((2x)2-2⋅(2x)⋅1+12)=0−((2x)2−2⋅(2x)⋅1+12)=0
Step 2.4.2.5
Factor using the perfect square trinomial rule a2-2ab+b2=(a-b)2a2−2ab+b2=(a−b)2, where a=2xa=2x and b=1b=1.
-(2x-1)2=0−(2x−1)2=0
-(2x-1)2=0−(2x−1)2=0
-(2x-1)2=0−(2x−1)2=0
Step 2.5
Divide each term in -(2x-1)2=0−(2x−1)2=0 by -1−1 and simplify.
Step 2.5.1
Divide each term in -(2x-1)2=0−(2x−1)2=0 by -1−1.
-(2x-1)2-1=0-1−(2x−1)2−1=0−1
Step 2.5.2
Simplify the left side.
Step 2.5.2.1
Dividing two negative values results in a positive value.
(2x-1)21=0-1(2x−1)21=0−1
Step 2.5.2.2
Divide (2x-1)2(2x−1)2 by 11.
(2x-1)2=0-1(2x−1)2=0−1
(2x-1)2=0-1(2x−1)2=0−1
Step 2.5.3
Simplify the right side.
Step 2.5.3.1
Divide 00 by -1−1.
(2x-1)2=0(2x−1)2=0
(2x-1)2=0(2x−1)2=0
(2x-1)2=0(2x−1)2=0
Step 2.6
Set the 2x-12x−1 equal to 00.
2x-1=02x−1=0
Step 2.7
Solve for xx.
Step 2.7.1
Add 11 to both sides of the equation.
2x=12x=1
Step 2.7.2
Divide each term in 2x=12x=1 by 22 and simplify.
Step 2.7.2.1
Divide each term in 2x=12x=1 by 22.
2x2=122x2=12
Step 2.7.2.2
Simplify the left side.
Step 2.7.2.2.1
Cancel the common factor of 22.
Step 2.7.2.2.1.1
Cancel the common factor.
2x2=12
Step 2.7.2.2.1.2
Divide x by 1.
x=12
x=12
x=12
x=12
x=12
x=12