r^2+6-91=0

Solution for r^2+6-91=0 equation:

Simplifying
r2 + 6 + -91 = 0

Reorder the terms:
6 + -91 + r2 = 0

Combine like terms: 6 + -91 = -85
-85 + r2 = 0

Solving
-85 + r2 = 0

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Add '85' to each side of the equation.
-85 + 85 + r2 = 0 + 85

Combine like terms: -85 + 85 = 0
0 + r2 = 0 + 85
r2 = 0 + 85

Combine like terms: 0 + 85 = 85
r2 = 85

Simplifying
r2 = 85

Take the square root of each side:
r = {-9.219544457, 9.219544457}