0=x^2-9x+72

Solution for 0=x^2-9x+72 equation:

Simplifying
0 = x2 + -9x + 72

Reorder the terms:
0 = 72 + -9x + x2

Solving
0 = 72 + -9x + x2

Solving for variable 'x'.

Combine like terms: 0 + -72 = -72
-72 + 9x + -1x2 = 72 + -9x + x2 + -72 + 9x + -1x2

Reorder the terms:
-72 + 9x + -1x2 = 72 + -72 + -9x + 9x + x2 + -1x2

Combine like terms: 72 + -72 = 0
-72 + 9x + -1x2 = 0 + -9x + 9x + x2 + -1x2
-72 + 9x + -1x2 = -9x + 9x + x2 + -1x2

Combine like terms: -9x + 9x = 0
-72 + 9x + -1x2 = 0 + x2 + -1x2
-72 + 9x + -1x2 = x2 + -1x2

Combine like terms: x2 + -1x2 = 0
-72 + 9x + -1x2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
72 + -9x + x2 = 0

Move the constant term to the right:

Add '-72' to each side of the equation.
72 + -9x + -72 + x2 = 0 + -72

Reorder the terms:
72 + -72 + -9x + x2 = 0 + -72

Combine like terms: 72 + -72 = 0
0 + -9x + x2 = 0 + -72
-9x + x2 = 0 + -72

Combine like terms: 0 + -72 = -72
-9x + x2 = -72

The x term is -9x.  Take half its coefficient (-4.5).
Square it (20.25) and add it to both sides.

Add '20.25' to each side of the equation.
-9x + 20.25 + x2 = -72 + 20.25

Reorder the terms:
20.25 + -9x + x2 = -72 + 20.25

Combine like terms: -72 + 20.25 = -51.75
20.25 + -9x + x2 = -51.75

Factor a perfect square on the left side:
(x + -4.5)(x + -4.5) = -51.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.