20r^2-45=0

Solution for 20r^2-45=0 equation:

Simplifying
20r2 + -45 = 0

Reorder the terms:
-45 + 20r2 = 0

Solving
-45 + 20r2 = 0

Solving for variable 'r'.

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

Add '45' to each side of the equation.
-45 + 45 + 20r2 = 0 + 45

Combine like terms: -45 + 45 = 0
0 + 20r2 = 0 + 45
20r2 = 0 + 45

Combine like terms: 0 + 45 = 45
20r2 = 45

Divide each side by '20'.
r2 = 2.25

Simplifying
r2 = 2.25

Take the square root of each side:
r = {-1.5, 1.5}