(4z-9)(5-z)=0

Solution for (4z-9)(5-z)=0 equation:

Simplifying
(4z + -9)(5 + -1z) = 0

Reorder the terms:
(-9 + 4z)(5 + -1z) = 0

Multiply (-9 + 4z) * (5 + -1z)
(-9(5 + -1z) + 4z * (5 + -1z)) = 0
((5 * -9 + -1z * -9) + 4z * (5 + -1z)) = 0
((-45 + 9z) + 4z * (5 + -1z)) = 0
(-45 + 9z + (5 * 4z + -1z * 4z)) = 0
(-45 + 9z + (20z + -4z2)) = 0

Combine like terms: 9z + 20z = 29z
(-45 + 29z + -4z2) = 0

Solving
-45 + 29z + -4z2 = 0

Solving for variable 'z'.

Factor a trinomial.
(-5 + z)(9 + -4z) = 0

Subproblem 1
Set the factor '(-5 + z)' equal to zero and attempt to solve:

Simplifying
-5 + z = 0

Solving
-5 + z = 0

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

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

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

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

Simplifying
z = 5
Subproblem 2
Set the factor '(9 + -4z)' equal to zero and attempt to solve:

Simplifying
9 + -4z = 0

Solving
9 + -4z = 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 + -4z = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -4z = 0 + -9
-4z = 0 + -9

Combine like terms: 0 + -9 = -9
-4z = -9

Divide each side by '-4'.
z = 2.25

Simplifying
z = 2.25
Solution
z = {5, 2.25}