(1-9r)(1+9r)=

Solution for (1-9r)(1+9r)= equation:

Simplifying
(1 + -9r)(1 + 9r) = 0

Multiply (1 + -9r) * (1 + 9r)
(1(1 + 9r) + -9r * (1 + 9r)) = 0
((1 * 1 + 9r * 1) + -9r * (1 + 9r)) = 0
((1 + 9r) + -9r * (1 + 9r)) = 0
(1 + 9r + (1 * -9r + 9r * -9r)) = 0
(1 + 9r + (-9r + -81r2)) = 0

Combine like terms: 9r + -9r = 0
(1 + 0 + -81r2) = 0
(1 + -81r2) = 0

Solving
1 + -81r2 = 0

Solving for variable 'r'.

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

Add '-1' to each side of the equation.
1 + -1 + -81r2 = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -81r2 = 0 + -1
-81r2 = 0 + -1

Combine like terms: 0 + -1 = -1
-81r2 = -1

Divide each side by '-81'.
r2 = 0.01234567901

Simplifying
r2 = 0.01234567901

Take the square root of each side:
r = {-0.111111111, 0.111111111}