x-x^2=72

Solution for x-x^2=72 equation:

Simplifying
x + -1x2 = 72

Solving
x + -1x2 = 72

Solving for variable 'x'.

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

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

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

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

Move the constant term to the right:

Add '-72' to each side of the equation.
72 + -1x + -72 + x2 = 0 + -72

Reorder the terms:
72 + -72 + -1x + x2 = 0 + -72

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

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

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1x + 0.25 + x2 = -72 + 0.25

Reorder the terms:
0.25 + -1x + x2 = -72 + 0.25

Combine like terms: -72 + 0.25 = -71.75
0.25 + -1x + x2 = -71.75

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = -71.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.