4r^2-121=0

Solution for 4r^2-121=0 equation:

Simplifying
4r2 + -121 = 0

Reorder the terms:
-121 + 4r2 = 0

Solving
-121 + 4r2 = 0

Solving for variable 'r'.

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

Add '121' to each side of the equation.
-121 + 121 + 4r2 = 0 + 121

Combine like terms: -121 + 121 = 0
0 + 4r2 = 0 + 121
4r2 = 0 + 121

Combine like terms: 0 + 121 = 121
4r2 = 121

Divide each side by '4'.
r2 = 30.25

Simplifying
r2 = 30.25

Take the square root of each side:
r = {-5.5, 5.5}