d^2+9d+8=0

Solution for d^2+9d+8=0 equation:

Simplifying
d2 + 9d + 8 = 0

Reorder the terms:
8 + 9d + d2 = 0

Solving
8 + 9d + d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(8 + d)(1 + d) = 0

Subproblem 1
Set the factor '(8 + d)' equal to zero and attempt to solve:

Simplifying
8 + d = 0

Solving
8 + d = 0

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

Add '-8' to each side of the equation.
8 + -8 + d = 0 + -8

Combine like terms: 8 + -8 = 0
0 + d = 0 + -8
d = 0 + -8

Combine like terms: 0 + -8 = -8
d = -8

Simplifying
d = -8
Subproblem 2
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
Solution
d = {-8, -1}