x^2+8x+91=0

Solution for x^2+8x+91=0 equation:

Simplifying
x2 + 8x + 91 = 0

Reorder the terms:
91 + 8x + x2 = 0

Solving
91 + 8x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '-91' to each side of the equation.
91 + 8x + -91 + x2 = 0 + -91

Reorder the terms:
91 + -91 + 8x + x2 = 0 + -91

Combine like terms: 91 + -91 = 0
0 + 8x + x2 = 0 + -91
8x + x2 = 0 + -91

Combine like terms: 0 + -91 = -91
8x + x2 = -91

The x term is 8x.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8x + 16 + x2 = -91 + 16

Reorder the terms:
16 + 8x + x2 = -91 + 16

Combine like terms: -91 + 16 = -75
16 + 8x + x2 = -75

Factor a perfect square on the left side:
(x + 4)(x + 4) = -75

Can't calculate square root of the right side.

The solution to this equation could not be determined.