9r^2-18r+1=-4

Solution for 9r^2-18r+1=-4 equation:

Simplifying
9r2 + -18r + 1 = -4

Reorder the terms:
1 + -18r + 9r2 = -4

Solving
1 + -18r + 9r2 = -4

Solving for variable 'r'.

Reorder the terms:
1 + 4 + -18r + 9r2 = -4 + 4

Combine like terms: 1 + 4 = 5
5 + -18r + 9r2 = -4 + 4

Combine like terms: -4 + 4 = 0
5 + -18r + 9r2 = 0

Factor a trinomial.
(1 + -3r)(5 + -3r) = 0

Subproblem 1
Set the factor '(1 + -3r)' equal to zero and attempt to solve:

Simplifying
1 + -3r = 0

Solving
1 + -3r = 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 + -3r = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -3r = 0 + -1
-3r = 0 + -1

Combine like terms: 0 + -1 = -1
-3r = -1

Divide each side by '-3'.
r = 0.3333333333

Simplifying
r = 0.3333333333
Subproblem 2
Set the factor '(5 + -3r)' equal to zero and attempt to solve:

Simplifying
5 + -3r = 0

Solving
5 + -3r = 0

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

Add '-5' to each side of the equation.
5 + -5 + -3r = 0 + -5

Combine like terms: 5 + -5 = 0
0 + -3r = 0 + -5
-3r = 0 + -5

Combine like terms: 0 + -5 = -5
-3r = -5

Divide each side by '-3'.
r = 1.666666667

Simplifying
r = 1.666666667
Solution
r = {0.3333333333, 1.666666667}