z^2-12z+25=0

Solution for z^2-12z+25=0 equation:

Simplifying
z2 + -12z + 25 = 0

Reorder the terms:
25 + -12z + z2 = 0

Solving
25 + -12z + z2 = 0

Solving for variable 'z'.

Begin completing the square.

Move the constant term to the right:

Add '-25' to each side of the equation.
25 + -12z + -25 + z2 = 0 + -25

Reorder the terms:
25 + -25 + -12z + z2 = 0 + -25

Combine like terms: 25 + -25 = 0
0 + -12z + z2 = 0 + -25
-12z + z2 = 0 + -25

Combine like terms: 0 + -25 = -25
-12z + z2 = -25

The z term is -12z.  Take half its coefficient (-6).
Square it (36) and add it to both sides.

Add '36' to each side of the equation.
-12z + 36 + z2 = -25 + 36

Reorder the terms:
36 + -12z + z2 = -25 + 36

Combine like terms: -25 + 36 = 11
36 + -12z + z2 = 11

Factor a perfect square on the left side:
(z + -6)(z + -6) = 11

Calculate the square root of the right side: 3.31662479

Break this problem into two subproblems by setting 
(z + -6) equal to 3.31662479 and -3.31662479.

Subproblem 1
z + -6 = 3.31662479

Simplifying
z + -6 = 3.31662479

Reorder the terms:
-6 + z = 3.31662479

Solving
-6 + z = 3.31662479

Solving for variable 'z'.

Move all terms containing z to the left, all other terms to the right.

Add '6' to each side of the equation.
-6 + 6 + z = 3.31662479 + 6

Combine like terms: -6 + 6 = 0
0 + z = 3.31662479 + 6
z = 3.31662479 + 6

Combine like terms: 3.31662479 + 6 = 9.31662479
z = 9.31662479

Simplifying
z = 9.31662479

Subproblem 2
z + -6 = -3.31662479

Simplifying
z + -6 = -3.31662479

Reorder the terms:
-6 + z = -3.31662479

Solving
-6 + z = -3.31662479

Solving for variable 'z'.

Move all terms containing z to the left, all other terms to the right.

Add '6' to each side of the equation.
-6 + 6 + z = -3.31662479 + 6

Combine like terms: -6 + 6 = 0
0 + z = -3.31662479 + 6
z = -3.31662479 + 6

Combine like terms: -3.31662479 + 6 = 2.68337521
z = 2.68337521

Simplifying
z = 2.68337521

Solution
The solution to the problem is based on the solutions
from the subproblems.
z = {9.31662479, 2.68337521}