0=-d^2+d+12

Solution for 0=-d^2+d+12 equation:

Simplifying
0 = -1d2 + d + 12

Reorder the terms:
0 = 12 + d + -1d2

Solving
0 = 12 + d + -1d2

Solving for variable 'd'.

Combine like terms: 0 + -12 = -12
-12 + -1d + d2 = 12 + d + -1d2 + -12 + -1d + d2

Reorder the terms:
-12 + -1d + d2 = 12 + -12 + d + -1d + -1d2 + d2

Combine like terms: 12 + -12 = 0
-12 + -1d + d2 = 0 + d + -1d + -1d2 + d2
-12 + -1d + d2 = d + -1d + -1d2 + d2

Combine like terms: d + -1d = 0
-12 + -1d + d2 = 0 + -1d2 + d2
-12 + -1d + d2 = -1d2 + d2

Combine like terms: -1d2 + d2 = 0
-12 + -1d + d2 = 0

Factor a trinomial.
(-3 + -1d)(4 + -1d) = 0

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

Simplifying
-3 + -1d = 0

Solving
-3 + -1d = 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 + -1d = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -1d = 0 + 3
-1d = 0 + 3

Combine like terms: 0 + 3 = 3
-1d = 3

Divide each side by '-1'.
d = -3

Simplifying
d = -3
Subproblem 2
Set the factor '(4 + -1d)' equal to zero and attempt to solve:

Simplifying
4 + -1d = 0

Solving
4 + -1d = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1d = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1d = 0 + -4
-1d = 0 + -4

Combine like terms: 0 + -4 = -4
-1d = -4

Divide each side by '-1'.
d = 4

Simplifying
d = 4
Solution
d = {-3, 4}