4a^2+15a+9=0

Solution for 4a^2+15a+9=0 equation:

Simplifying
4a2 + 15a + 9 = 0

Reorder the terms:
9 + 15a + 4a2 = 0

Solving
9 + 15a + 4a2 = 0

Solving for variable 'a'.

Factor a trinomial.
(3 + a)(3 + 4a) = 0

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

Simplifying
3 + a = 0

Solving
3 + a = 0

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

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

Combine like terms: 3 + -3 = 0
0 + a = 0 + -3
a = 0 + -3

Combine like terms: 0 + -3 = -3
a = -3

Simplifying
a = -3
Subproblem 2
Set the factor '(3 + 4a)' equal to zero and attempt to solve:

Simplifying
3 + 4a = 0

Solving
3 + 4a = 0

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

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

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

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

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

Simplifying
a = -0.75
Solution
a = {-3, -0.75}