7(r+4)(r-4)=0

Solution for 7(r+4)(r-4)=0 equation:

Simplifying
7(r + 4)(r + -4) = 0

Reorder the terms:
7(4 + r)(r + -4) = 0

Reorder the terms:
7(4 + r)(-4 + r) = 0

Multiply (4 + r) * (-4 + r)
7(4(-4 + r) + r(-4 + r)) = 0
7((-4 * 4 + r * 4) + r(-4 + r)) = 0
7((-16 + 4r) + r(-4 + r)) = 0
7(-16 + 4r + (-4 * r + r * r)) = 0
7(-16 + 4r + (-4r + r2)) = 0

Combine like terms: 4r + -4r = 0
7(-16 + 0 + r2) = 0
7(-16 + r2) = 0
(-16 * 7 + r2 * 7) = 0
(-112 + 7r2) = 0

Solving
-112 + 7r2 = 0

Solving for variable 'r'.

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

Add '112' to each side of the equation.
-112 + 112 + 7r2 = 0 + 112

Combine like terms: -112 + 112 = 0
0 + 7r2 = 0 + 112
7r2 = 0 + 112

Combine like terms: 0 + 112 = 112
7r2 = 112

Divide each side by '7'.
r2 = 16

Simplifying
r2 = 16

Take the square root of each side:
r = {-4, 4}