A^2=A-20

Solution for A^2=A-20 equation:

Simplifying
A2 = A + -20

Reorder the terms:
A2 = -20 + A

Solving
A2 = -20 + A

Solving for variable 'A'.

Reorder the terms:
20 + -1A + A2 = -20 + A + 20 + -1A

Reorder the terms:
20 + -1A + A2 = -20 + 20 + A + -1A

Combine like terms: -20 + 20 = 0
20 + -1A + A2 = 0 + A + -1A
20 + -1A + A2 = A + -1A

Combine like terms: A + -1A = 0
20 + -1A + A2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-20' to each side of the equation.
20 + -1A + -20 + A2 = 0 + -20

Reorder the terms:
20 + -20 + -1A + A2 = 0 + -20

Combine like terms: 20 + -20 = 0
0 + -1A + A2 = 0 + -20
-1A + A2 = 0 + -20

Combine like terms: 0 + -20 = -20
-1A + A2 = -20

The A term is -1A.  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.
-1A + 0.25 + A2 = -20 + 0.25

Reorder the terms:
0.25 + -1A + A2 = -20 + 0.25

Combine like terms: -20 + 0.25 = -19.75
0.25 + -1A + A2 = -19.75

Factor a perfect square on the left side:
(A + -0.5)(A + -0.5) = -19.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.