7(r-2)(r+2)=0

Solution for 7(r-2)(r+2)=0 equation:

Simplifying
7(r + -2)(r + 2) = 0

Reorder the terms:
7(-2 + r)(r + 2) = 0

Reorder the terms:
7(-2 + r)(2 + r) = 0

Multiply (-2 + r) * (2 + r)
7(-2(2 + r) + r(2 + r)) = 0
7((2 * -2 + r * -2) + r(2 + r)) = 0
7((-4 + -2r) + r(2 + r)) = 0
7(-4 + -2r + (2 * r + r * r)) = 0
7(-4 + -2r + (2r + r2)) = 0

Combine like terms: -2r + 2r = 0
7(-4 + 0 + r2) = 0
7(-4 + r2) = 0
(-4 * 7 + r2 * 7) = 0
(-28 + 7r2) = 0

Solving
-28 + 7r2 = 0

Solving for variable 'r'.

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

Add '28' to each side of the equation.
-28 + 28 + 7r2 = 0 + 28

Combine like terms: -28 + 28 = 0
0 + 7r2 = 0 + 28
7r2 = 0 + 28

Combine like terms: 0 + 28 = 28
7r2 = 28

Divide each side by '7'.
r2 = 4

Simplifying
r2 = 4

Take the square root of each side:
r = {-2, 2}