Examples
y=x2-6x+16
Step 1
Plug in 0 for y.
0=x2-6x+16
Step 2
Step 2.1
Remove parentheses.
0=x2-6x+16
Step 2.2
Since x is on the right side of the equation, switch the sides so it is on the left side of the equation.
x2-6x+16=0
Step 2.3
Subtract 16 from both sides of the equation.
x2-6x=-16
x2-6x=-16
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=(-3)2
Step 4
Add the term to each side of the equation.
x2-6x+(-3)2=-16+(-3)2
Step 5
Step 5.1
Simplify the left side.
Step 5.1.1
Raise -3 to the power of 2.
x2-6x+9=-16+(-3)2
x2-6x+9=-16+(-3)2
Step 5.2
Simplify the right side.
Step 5.2.1
Simplify -16+(-3)2.
Step 5.2.1.1
Raise -3 to the power of 2.
x2-6x+9=-16+9
Step 5.2.1.2
Add -16 and 9.
x2-6x+9=-7
x2-6x+9=-7
x2-6x+9=-7
x2-6x+9=-7
Step 6
Factor the perfect trinomial square into (x-3)2.
(x-3)2=-7
Step 7
Step 7.1
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
x-3=±√-7
Step 7.2
Simplify ±√-7.
Step 7.2.1
Rewrite -7 as -1(7).
x-3=±√-1(7)
Step 7.2.2
Rewrite √-1(7) as √-1⋅√7.
x-3=±√-1⋅√7
Step 7.2.3
Rewrite √-1 as i.
x-3=±i√7
x-3=±i√7
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-3=i√7
Step 7.3.2
Add 3 to both sides of the equation.
x=i√7+3
Step 7.3.3
Next, use the negative value of the ± to find the second solution.
x-3=-i√7
Step 7.3.4
Add 3 to both sides of the equation.
x=-i√7+3
Step 7.3.5
The complete solution is the result of both the positive and negative portions of the solution.
x=i√7+3,-i√7+3
x=i√7+3,-i√7+3
x=i√7+3,-i√7+3