(d-9)(3d+7)=

Solution for (d-9)(3d+7)= equation:

Simplifying
(d + -9)(3d + 7) = 0

Reorder the terms:
(-9 + d)(3d + 7) = 0

Reorder the terms:
(-9 + d)(7 + 3d) = 0

Multiply (-9 + d) * (7 + 3d)
(-9(7 + 3d) + d(7 + 3d)) = 0
((7 * -9 + 3d * -9) + d(7 + 3d)) = 0
((-63 + -27d) + d(7 + 3d)) = 0
(-63 + -27d + (7 * d + 3d * d)) = 0
(-63 + -27d + (7d + 3d2)) = 0

Combine like terms: -27d + 7d = -20d
(-63 + -20d + 3d2) = 0

Solving
-63 + -20d + 3d2 = 0

Solving for variable 'd'.

Factor a trinomial.
(-7 + -3d)(9 + -1d) = 0

Subproblem 1
Set the factor '(-7 + -3d)' equal to zero and attempt to solve:

Simplifying
-7 + -3d = 0

Solving
-7 + -3d = 0

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

Add '7' to each side of the equation.
-7 + 7 + -3d = 0 + 7

Combine like terms: -7 + 7 = 0
0 + -3d = 0 + 7
-3d = 0 + 7

Combine like terms: 0 + 7 = 7
-3d = 7

Divide each side by '-3'.
d = -2.333333333

Simplifying
d = -2.333333333
Subproblem 2
Set the factor '(9 + -1d)' equal to zero and attempt to solve:

Simplifying
9 + -1d = 0

Solving
9 + -1d = 0

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

Add '-9' to each side of the equation.
9 + -9 + -1d = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -1d = 0 + -9
-1d = 0 + -9

Combine like terms: 0 + -9 = -9
-1d = -9

Divide each side by '-1'.
d = 9

Simplifying
d = 9
Solution
d = {-2.333333333, 9}