4d^2+15d+9=

Solution for 4d^2+15d+9= equation:

Simplifying
4d2 + 15d + 9 = 0

Reorder the terms:
9 + 15d + 4d2 = 0

Solving
9 + 15d + 4d2 = 0

Solving for variable 'd'.

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

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

Simplifying
3 + d = 0

Solving
3 + d = 0

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

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

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

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

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

Simplifying
3 + 4d = 0

Solving
3 + 4d = 0

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

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

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

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

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

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