8(r-5)(r+5)=0

Solution for 8(r-5)(r+5)=0 equation:

Simplifying
8(r + -5)(r + 5) = 0

Reorder the terms:
8(-5 + r)(r + 5) = 0

Reorder the terms:
8(-5 + r)(5 + r) = 0

Multiply (-5 + r) * (5 + r)
8(-5(5 + r) + r(5 + r)) = 0
8((5 * -5 + r * -5) + r(5 + r)) = 0
8((-25 + -5r) + r(5 + r)) = 0
8(-25 + -5r + (5 * r + r * r)) = 0
8(-25 + -5r + (5r + r2)) = 0

Combine like terms: -5r + 5r = 0
8(-25 + 0 + r2) = 0
8(-25 + r2) = 0
(-25 * 8 + r2 * 8) = 0
(-200 + 8r2) = 0

Solving
-200 + 8r2 = 0

Solving for variable 'r'.

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

Add '200' to each side of the equation.
-200 + 200 + 8r2 = 0 + 200

Combine like terms: -200 + 200 = 0
0 + 8r2 = 0 + 200
8r2 = 0 + 200

Combine like terms: 0 + 200 = 200
8r2 = 200

Divide each side by '8'.
r2 = 25

Simplifying
r2 = 25

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