0=r(r)-110.25

Solution for 0=r(r)-110.25 equation:

Simplifying
0 = r(r) + -110.25

Multiply r * r
0 = r2 + -110.25

Reorder the terms:
0 = -110.25 + r2

Solving
0 = -110.25 + r2

Solving for variable 'r'.

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

Add '-1r2' to each side of the equation.
0 + -1r2 = -110.25 + r2 + -1r2
Remove the zero:
-1r2 = -110.25 + r2 + -1r2

Combine like terms: r2 + -1r2 = 0
-1r2 = -110.25 + 0
-1r2 = -110.25

Divide each side by '-1'.
r2 = 110.25

Simplifying
r2 = 110.25

Take the square root of each side:
r = {-10.5, 10.5}