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

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

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

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

Multiply (-9 + 5z) * (5 + z)
(-9(5 + z) + 5z * (5 + z)) = 0
((5 * -9 + z * -9) + 5z * (5 + z)) = 0
((-45 + -9z) + 5z * (5 + z)) = 0
(-45 + -9z + (5 * 5z + z * 5z)) = 0
(-45 + -9z + (25z + 5z2)) = 0

Combine like terms: -9z + 25z = 16z
(-45 + 16z + 5z2) = 0

Solving
-45 + 16z + 5z2 = 0

Solving for variable 'z'.

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

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

Simplifying
-5 + -1z = 0

Solving
-5 + -1z = 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 + -1z = 0 + 5

Combine like terms: -5 + 5 = 0
0 + -1z = 0 + 5
-1z = 0 + 5

Combine like terms: 0 + 5 = 5
-1z = 5

Divide each side by '-1'.
z = -5

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

Simplifying
9 + -5z = 0

Solving
9 + -5z = 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 + -5z = 0 + -9

Combine like terms: 9 + -9 = 0
0 + -5z = 0 + -9
-5z = 0 + -9

Combine like terms: 0 + -9 = -9
-5z = -9

Divide each side by '-5'.
z = 1.8

Simplifying
z = 1.8
Solution
z = {-5, 1.8}