=4r^2+15r-4

Solution for =4r^2+15r-4 equation:

Simplifying
0 = 4r2 + 15r + -4

Reorder the terms:
0 = -4 + 15r + 4r2

Solving
0 = -4 + 15r + 4r2

Solving for variable 'r'.

Combine like terms: 0 + 4 = 4
4 + -15r + -4r2 = -4 + 15r + 4r2 + 4 + -15r + -4r2

Reorder the terms:
4 + -15r + -4r2 = -4 + 4 + 15r + -15r + 4r2 + -4r2

Combine like terms: -4 + 4 = 0
4 + -15r + -4r2 = 0 + 15r + -15r + 4r2 + -4r2
4 + -15r + -4r2 = 15r + -15r + 4r2 + -4r2

Combine like terms: 15r + -15r = 0
4 + -15r + -4r2 = 0 + 4r2 + -4r2
4 + -15r + -4r2 = 4r2 + -4r2

Combine like terms: 4r2 + -4r2 = 0
4 + -15r + -4r2 = 0

Factor a trinomial.
(1 + -4r)(4 + r) = 0

Subproblem 1
Set the factor '(1 + -4r)' equal to zero and attempt to solve:

Simplifying
1 + -4r = 0

Solving
1 + -4r = 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 + -4r = 0 + -1

Combine like terms: 1 + -1 = 0
0 + -4r = 0 + -1
-4r = 0 + -1

Combine like terms: 0 + -1 = -1
-4r = -1

Divide each side by '-4'.
r = 0.25

Simplifying
r = 0.25
Subproblem 2
Set the factor '(4 + r)' equal to zero and attempt to solve:

Simplifying
4 + r = 0

Solving
4 + r = 0

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

Add '-4' to each side of the equation.
4 + -4 + r = 0 + -4

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

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

Simplifying
r = -4
Solution
r = {0.25, -4}