x^2+16x+91=0

Solution for x^2+16x+91=0 equation:

Simplifying
x2 + 16x + 91 = 0

Reorder the terms:
91 + 16x + x2 = 0

Solving
91 + 16x + 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 + 16x + -91 + x2 = 0 + -91

Reorder the terms:
91 + -91 + 16x + x2 = 0 + -91

Combine like terms: 91 + -91 = 0
0 + 16x + x2 = 0 + -91
16x + x2 = 0 + -91

Combine like terms: 0 + -91 = -91
16x + x2 = -91

The x term is 16x.  Take half its coefficient (8).
Square it (64) and add it to both sides.

Add '64' to each side of the equation.
16x + 64 + x2 = -91 + 64

Reorder the terms:
64 + 16x + x2 = -91 + 64

Combine like terms: -91 + 64 = -27
64 + 16x + x2 = -27

Factor a perfect square on the left side:
(x + 8)(x + 8) = -27

Can't calculate square root of the right side.

The solution to this equation could not be determined.