4r^2-169=0

Solution for 4r^2-169=0 equation:

Simplifying
4r2 + -169 = 0

Reorder the terms:
-169 + 4r2 = 0

Solving
-169 + 4r2 = 0

Solving for variable 'r'.

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

Add '169' to each side of the equation.
-169 + 169 + 4r2 = 0 + 169

Combine like terms: -169 + 169 = 0
0 + 4r2 = 0 + 169
4r2 = 0 + 169

Combine like terms: 0 + 169 = 169
4r2 = 169

Divide each side by '4'.
r2 = 42.25

Simplifying
r2 = 42.25

Take the square root of each side:
r = {-6.5, 6.5}