-8d^2+26d+15=0

Solution for -8d^2+26d+15=0 equation:

Simplifying
-8d2 + 26d + 15 = 0

Reorder the terms:
15 + 26d + -8d2 = 0

Solving
15 + 26d + -8d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(15 + -4d)(1 + 2d) = 0

Subproblem 1
Set the factor '(15 + -4d)' equal to zero and attempt to solve:

Simplifying
15 + -4d = 0

Solving
15 + -4d = 0

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

Add '-15' to each side of the equation.
15 + -15 + -4d = 0 + -15

Combine like terms: 15 + -15 = 0
0 + -4d = 0 + -15
-4d = 0 + -15

Combine like terms: 0 + -15 = -15
-4d = -15

Divide each side by '-4'.
d = 3.75

Simplifying
d = 3.75
Subproblem 2
Set the factor '(1 + 2d)' equal to zero and attempt to solve:

Simplifying
1 + 2d = 0

Solving
1 + 2d = 0

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

Add '-1' to each side of the equation.
1 + -1 + 2d = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 2d = 0 + -1
2d = 0 + -1

Combine like terms: 0 + -1 = -1
2d = -1

Divide each side by '2'.
d = -0.5

Simplifying
d = -0.5
Solution
d = {3.75, -0.5}