4d^2+21d-18=0

Solution for 4d^2+21d-18=0 equation:

Simplifying
4d2 + 21d + -18 = 0

Reorder the terms:
-18 + 21d + 4d2 = 0

Solving
-18 + 21d + 4d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(-6 + -1d)(3 + -4d) = 0

Subproblem 1
Set the factor '(-6 + -1d)' equal to zero and attempt to solve:

Simplifying
-6 + -1d = 0

Solving
-6 + -1d = 0

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

Add '6' to each side of the equation.
-6 + 6 + -1d = 0 + 6

Combine like terms: -6 + 6 = 0
0 + -1d = 0 + 6
-1d = 0 + 6

Combine like terms: 0 + 6 = 6
-1d = 6

Divide each side by '-1'.
d = -6

Simplifying
d = -6
Subproblem 2
Set the factor '(3 + -4d)' equal to zero and attempt to solve:

Simplifying
3 + -4d = 0

Solving
3 + -4d = 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 + -4d = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -4d = 0 + -3
-4d = 0 + -3

Combine like terms: 0 + -3 = -3
-4d = -3

Divide each side by '-4'.
d = 0.75

Simplifying
d = 0.75
Solution
d = {-6, 0.75}