(r-3)(r+3)=

Solution for (r-3)(r+3)= equation:

Simplifying
(r + -3)(r + 3) = 0

Reorder the terms:
(-3 + r)(r + 3) = 0

Reorder the terms:
(-3 + r)(3 + r) = 0

Multiply (-3 + r) * (3 + r)
(-3(3 + r) + r(3 + r)) = 0
((3 * -3 + r * -3) + r(3 + r)) = 0
((-9 + -3r) + r(3 + r)) = 0
(-9 + -3r + (3 * r + r * r)) = 0
(-9 + -3r + (3r + r2)) = 0

Combine like terms: -3r + 3r = 0
(-9 + 0 + r2) = 0
(-9 + r2) = 0

Solving
-9 + r2 = 0

Solving for variable 'r'.

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

Add '9' to each side of the equation.
-9 + 9 + r2 = 0 + 9

Combine like terms: -9 + 9 = 0
0 + r2 = 0 + 9
r2 = 0 + 9

Combine like terms: 0 + 9 = 9
r2 = 9

Simplifying
r2 = 9

Take the square root of each side:
r = {-3, 3}