100=4r^2

Solution for 100=4r^2 equation:

Simplifying
100 = 4r2

Solving
100 = 4r2

Solving for variable 'r'.

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

Add '-4r2' to each side of the equation.
100 + -4r2 = 4r2 + -4r2

Combine like terms: 4r2 + -4r2 = 0
100 + -4r2 = 0

Add '-100' to each side of the equation.
100 + -100 + -4r2 = 0 + -100

Combine like terms: 100 + -100 = 0
0 + -4r2 = 0 + -100
-4r2 = 0 + -100

Combine like terms: 0 + -100 = -100
-4r2 = -100

Divide each side by '-4'.
r2 = 25

Simplifying
r2 = 25

Take the square root of each side:
r = {-5, 5}