r^2-4r-1=-4

Solution for r^2-4r-1=-4 equation:

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

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

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

Solving for variable 'r'.

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

Combine like terms: -1 + 4 = 3
3 + -4r + r2 = -4 + 4

Combine like terms: -4 + 4 = 0
3 + -4r + r2 = 0

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

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

Simplifying
1 + -1r = 0

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

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

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

Divide each side by '-1'.
r = 1

Simplifying
r = 1
Subproblem 2
Set the factor '(3 + -1r)' equal to zero and attempt to solve:

Simplifying
3 + -1r = 0

Solving
3 + -1r = 0

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

Add '-3' to each side of the equation.
3 + -3 + -1r = 0 + -3

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

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

Divide each side by '-1'.
r = 3

Simplifying
r = 3
Solution
r = {1, 3}