0=-8r+5-4r^2

Solution for 0=-8r+5-4r^2 equation:

Simplifying
0 = -8r + 5 + -4r2

Reorder the terms:
0 = 5 + -8r + -4r2

Solving
0 = 5 + -8r + -4r2

Solving for variable 'r'.

Combine like terms: 0 + -5 = -5
-5 + 8r + 4r2 = 5 + -8r + -4r2 + -5 + 8r + 4r2

Reorder the terms:
-5 + 8r + 4r2 = 5 + -5 + -8r + 8r + -4r2 + 4r2

Combine like terms: 5 + -5 = 0
-5 + 8r + 4r2 = 0 + -8r + 8r + -4r2 + 4r2
-5 + 8r + 4r2 = -8r + 8r + -4r2 + 4r2

Combine like terms: -8r + 8r = 0
-5 + 8r + 4r2 = 0 + -4r2 + 4r2
-5 + 8r + 4r2 = -4r2 + 4r2

Combine like terms: -4r2 + 4r2 = 0
-5 + 8r + 4r2 = 0

Factor a trinomial.
(-5 + -2r)(1 + -2r) = 0

Subproblem 1
Set the factor '(-5 + -2r)' equal to zero and attempt to solve:

Simplifying
-5 + -2r = 0

Solving
-5 + -2r = 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 + -2r = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -2r = 0 + 5
-2r = 0 + 5

Combine like terms: 0 + 5 = 5
-2r = 5

Divide each side by '-2'.
r = -2.5

Simplifying
r = -2.5
Subproblem 2
Set the factor '(1 + -2r)' equal to zero and attempt to solve:

Simplifying
1 + -2r = 0

Solving
1 + -2r = 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 + -2r = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -2r = 0 + -1
-2r = 0 + -1

Combine like terms: 0 + -1 = -1
-2r = -1

Divide each side by '-2'.
r = 0.5

Simplifying
r = 0.5
Solution
r = {-2.5, 0.5}