-7d^2-8d-1=0

Solution for -7d^2-8d-1=0 equation:

Simplifying
-7d2 + -8d + -1 = 0

Reorder the terms:
-1 + -8d + -7d2 = 0

Solving
-1 + -8d + -7d2 = 0

Solving for variable 'd'.

Factor out the Greatest Common Factor (GCF), '-1'.
-1(1 + 8d + 7d2) = 0

Factor a trinomial.
-1((1 + d)(1 + 7d)) = 0

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

Simplifying
1 + d = 0

Solving
1 + d = 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 + d = 0 + -1

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

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

Simplifying
d = -1
Subproblem 2
Set the factor '(1 + 7d)' equal to zero and attempt to solve:

Simplifying
1 + 7d = 0

Solving
1 + 7d = 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 + 7d = 0 + -1

Combine like terms: 1 + -1 = 0
0 + 7d = 0 + -1
7d = 0 + -1

Combine like terms: 0 + -1 = -1
7d = -1

Divide each side by '7'.
d = -0.1428571429

Simplifying
d = -0.1428571429
Solution
d = {-1, -0.1428571429}