7r^2-20=0

Solution for 7r^2-20=0 equation:

Simplifying
7r2 + -20 = 0

Reorder the terms:
-20 + 7r2 = 0

Solving
-20 + 7r2 = 0

Solving for variable 'r'.

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

Add '20' to each side of the equation.
-20 + 20 + 7r2 = 0 + 20

Combine like terms: -20 + 20 = 0
0 + 7r2 = 0 + 20
7r2 = 0 + 20

Combine like terms: 0 + 20 = 20
7r2 = 20

Divide each side by '7'.
r2 = 2.857142857

Simplifying
r2 = 2.857142857

Take the square root of each side:
r = {-1.690308509, 1.690308509}