z^2-11z+90=0

Solution for z^2-11z+90=0 equation:

Simplifying
z2 + -11z + 90 = 0

Reorder the terms:
90 + -11z + z2 = 0

Solving
90 + -11z + z2 = 0

Solving for variable 'z'.

Begin completing the square.

Move the constant term to the right:

Add '-90' to each side of the equation.
90 + -11z + -90 + z2 = 0 + -90

Reorder the terms:
90 + -90 + -11z + z2 = 0 + -90

Combine like terms: 90 + -90 = 0
0 + -11z + z2 = 0 + -90
-11z + z2 = 0 + -90

Combine like terms: 0 + -90 = -90
-11z + z2 = -90

The z term is -11z.  Take half its coefficient (-5.5).
Square it (30.25) and add it to both sides.

Add '30.25' to each side of the equation.
-11z + 30.25 + z2 = -90 + 30.25

Reorder the terms:
30.25 + -11z + z2 = -90 + 30.25

Combine like terms: -90 + 30.25 = -59.75
30.25 + -11z + z2 = -59.75

Factor a perfect square on the left side:
(z + -5.5)(z + -5.5) = -59.75

Can't calculate square root of the right side.

The solution to this equation could not be determined.