(5z+6)(9-z)=0

Solution for (5z+6)(9-z)=0 equation:

Simplifying
(5z + 6)(9 + -1z) = 0

Reorder the terms:
(6 + 5z)(9 + -1z) = 0

Multiply (6 + 5z) * (9 + -1z)
(6(9 + -1z) + 5z * (9 + -1z)) = 0
((9 * 6 + -1z * 6) + 5z * (9 + -1z)) = 0
((54 + -6z) + 5z * (9 + -1z)) = 0
(54 + -6z + (9 * 5z + -1z * 5z)) = 0
(54 + -6z + (45z + -5z2)) = 0

Combine like terms: -6z + 45z = 39z
(54 + 39z + -5z2) = 0

Solving
54 + 39z + -5z2 = 0

Solving for variable 'z'.

Factor a trinomial.
(9 + -1z)(6 + 5z) = 0

Subproblem 1
Set the factor '(9 + -1z)' equal to zero and attempt to solve:

Simplifying
9 + -1z = 0

Solving
9 + -1z = 0

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

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

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

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

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

Simplifying
z = 9
Subproblem 2
Set the factor '(6 + 5z)' equal to zero and attempt to solve:

Simplifying
6 + 5z = 0

Solving
6 + 5z = 0

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

Add '-6' to each side of the equation.
6 + -6 + 5z = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 5z = 0 + -6
5z = 0 + -6

Combine like terms: 0 + -6 = -6
5z = -6

Divide each side by '5'.
z = -1.2

Simplifying
z = -1.2
Solution
z = {9, -1.2}