z^2-z+20=0

Solution for z^2-z+20=0 equation:

Simplifying
z2 + -1z + 20 = 0

Reorder the terms:
20 + -1z + z2 = 0

Solving
20 + -1z + z2 = 0

Solving for variable 'z'.

Begin completing the square.

Move the constant term to the right:

Add '-20' to each side of the equation.
20 + -1z + -20 + z2 = 0 + -20

Reorder the terms:
20 + -20 + -1z + z2 = 0 + -20

Combine like terms: 20 + -20 = 0
0 + -1z + z2 = 0 + -20
-1z + z2 = 0 + -20

Combine like terms: 0 + -20 = -20
-1z + z2 = -20

The z term is -1z.  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.
-1z + 0.25 + z2 = -20 + 0.25

Reorder the terms:
0.25 + -1z + z2 = -20 + 0.25

Combine like terms: -20 + 0.25 = -19.75
0.25 + -1z + z2 = -19.75

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

Can't calculate square root of the right side.

The solution to this equation could not be determined.