-9+3k+20k^2=0

Solution for -9+3k+20k^2=0 equation:

Simplifying
-9 + 3k + 20k2 = 0

Solving
-9 + 3k + 20k2 = 0

Solving for variable 'k'.

Factor a trinomial.
(-3 + -4k)(3 + -5k) = 0

Subproblem 1
Set the factor '(-3 + -4k)' equal to zero and attempt to solve:

Simplifying
-3 + -4k = 0

Solving
-3 + -4k = 0

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

Add '3' to each side of the equation.
-3 + 3 + -4k = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -4k = 0 + 3
-4k = 0 + 3

Combine like terms: 0 + 3 = 3
-4k = 3

Divide each side by '-4'.
k = -0.75

Simplifying
k = -0.75
Subproblem 2
Set the factor '(3 + -5k)' equal to zero and attempt to solve:

Simplifying
3 + -5k = 0

Solving
3 + -5k = 0

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

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

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

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

Divide each side by '-5'.
k = 0.6

Simplifying
k = 0.6
Solution
k = {-0.75, 0.6}