99r^2+2r-1=0

Solution for 99r^2+2r-1=0 equation:

Simplifying
99r2 + 2r + -1 = 0

Reorder the terms:
-1 + 2r + 99r2 = 0

Solving
-1 + 2r + 99r2 = 0

Solving for variable 'r'.

Factor a trinomial.
(-1 + -9r)(1 + -11r) = 0

Subproblem 1
Set the factor '(-1 + -9r)' equal to zero and attempt to solve:

Simplifying
-1 + -9r = 0

Solving
-1 + -9r = 0

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

Add '1' to each side of the equation.
-1 + 1 + -9r = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -9r = 0 + 1
-9r = 0 + 1

Combine like terms: 0 + 1 = 1
-9r = 1

Divide each side by '-9'.
r = -0.1111111111

Simplifying
r = -0.1111111111
Subproblem 2
Set the factor '(1 + -11r)' equal to zero and attempt to solve:

Simplifying
1 + -11r = 0

Solving
1 + -11r = 0

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

Add '-1' to each side of the equation.
1 + -1 + -11r = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -11r = 0 + -1
-11r = 0 + -1

Combine like terms: 0 + -1 = -1
-11r = -1

Divide each side by '-11'.
r = 0.09090909091

Simplifying
r = 0.09090909091
Solution
r = {-0.1111111111, 0.09090909091}