90=-2d^2+36d

Solution for 90=-2d^2+36d equation:

Simplifying
90 = -2d2 + 36d

Reorder the terms:
90 = 36d + -2d2

Solving
90 = 36d + -2d2

Solving for variable 'd'.

Reorder the terms:
90 + -36d + 2d2 = 36d + -36d + -2d2 + 2d2

Combine like terms: 36d + -36d = 0
90 + -36d + 2d2 = 0 + -2d2 + 2d2
90 + -36d + 2d2 = -2d2 + 2d2

Combine like terms: -2d2 + 2d2 = 0
90 + -36d + 2d2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(45 + -18d + d2) = 0

Factor a trinomial.
2((3 + -1d)(15 + -1d)) = 0

Ignore the factor 2.
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 '(15 + -1d)' equal to zero and attempt to solve:

Simplifying
15 + -1d = 0

Solving
15 + -1d = 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 + -1d = 0 + -15

Combine like terms: 15 + -15 = 0
0 + -1d = 0 + -15
-1d = 0 + -15

Combine like terms: 0 + -15 = -15
-1d = -15

Divide each side by '-1'.
d = 15

Simplifying
d = 15
Solution
d = {3, 15}