15+26d=-8d^2

Solution for 15+26d=-8d^2 equation:

Simplifying
15 + 26d = -8d2

Solving
15 + 26d = -8d2

Solving for variable 'd'.

Combine like terms: -8d2 + 8d2 = 0
15 + 26d + 8d2 = 0

Factor a trinomial.
(5 + 2d)(3 + 4d) = 0

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

Simplifying
5 + 2d = 0

Solving
5 + 2d = 0

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

Add '-5' to each side of the equation.
5 + -5 + 2d = 0 + -5

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

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

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

Simplifying
d = -2.5
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 = {-2.5, -0.75}