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

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

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

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

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

Multiply (-9 + s) * (5 + s)
(-9(5 + s) + s(5 + s)) = 0
((5 * -9 + s * -9) + s(5 + s)) = 0
((-45 + -9s) + s(5 + s)) = 0
(-45 + -9s + (5 * s + s * s)) = 0
(-45 + -9s + (5s + s2)) = 0

Combine like terms: -9s + 5s = -4s
(-45 + -4s + s2) = 0

Solving
-45 + -4s + s2 = 0

Solving for variable 's'.

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

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

Simplifying
-5 + -1s = 0

Solving
-5 + -1s = 0

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

Add '5' to each side of the equation.
-5 + 5 + -1s = 0 + 5

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

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

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

Simplifying
s = -5
Subproblem 2
Set the factor '(9 + -1s)' equal to zero and attempt to solve:

Simplifying
9 + -1s = 0

Solving
9 + -1s = 0

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

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

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

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

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

Simplifying
s = 9
Solution
s = {-5, 9}