20r^2-245=0

Solution for 20r^2-245=0 equation:

Simplifying
20r2 + -245 = 0

Reorder the terms:
-245 + 20r2 = 0

Solving
-245 + 20r2 = 0

Solving for variable 'r'.

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

Add '245' to each side of the equation.
-245 + 245 + 20r2 = 0 + 245

Combine like terms: -245 + 245 = 0
0 + 20r2 = 0 + 245
20r2 = 0 + 245

Combine like terms: 0 + 245 = 245
20r2 = 245

Divide each side by '20'.
r2 = 12.25

Simplifying
r2 = 12.25

Take the square root of each side:
r = {-3.5, 3.5}