20=(s-8)(s-9)

Solution for 20=(s-8)(s-9) equation:

Simplifying
20 = (s + -8)(s + -9)

Reorder the terms:
20 = (-8 + s)(s + -9)

Reorder the terms:
20 = (-8 + s)(-9 + s)

Multiply (-8 + s) * (-9 + s)
20 = (-8(-9 + s) + s(-9 + s))
20 = ((-9 * -8 + s * -8) + s(-9 + s))
20 = ((72 + -8s) + s(-9 + s))
20 = (72 + -8s + (-9 * s + s * s))
20 = (72 + -8s + (-9s + s2))

Combine like terms: -8s + -9s = -17s
20 = (72 + -17s + s2)

Solving
20 = 72 + -17s + s2

Solving for variable 's'.

Combine like terms: 20 + -72 = -52
-52 + 17s + -1s2 = 72 + -17s + s2 + -72 + 17s + -1s2

Reorder the terms:
-52 + 17s + -1s2 = 72 + -72 + -17s + 17s + s2 + -1s2

Combine like terms: 72 + -72 = 0
-52 + 17s + -1s2 = 0 + -17s + 17s + s2 + -1s2
-52 + 17s + -1s2 = -17s + 17s + s2 + -1s2

Combine like terms: -17s + 17s = 0
-52 + 17s + -1s2 = 0 + s2 + -1s2
-52 + 17s + -1s2 = s2 + -1s2

Combine like terms: s2 + -1s2 = 0
-52 + 17s + -1s2 = 0

Factor a trinomial.
(-13 + s)(4 + -1s) = 0

Subproblem 1
Set the factor '(-13 + s)' equal to zero and attempt to solve:

Simplifying
-13 + s = 0

Solving
-13 + s = 0

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

Add '13' to each side of the equation.
-13 + 13 + s = 0 + 13

Combine like terms: -13 + 13 = 0
0 + s = 0 + 13
s = 0 + 13

Combine like terms: 0 + 13 = 13
s = 13

Simplifying
s = 13
Subproblem 2
Set the factor '(4 + -1s)' equal to zero and attempt to solve:

Simplifying
4 + -1s = 0

Solving
4 + -1s = 0

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

Add '-4' to each side of the equation.
4 + -4 + -1s = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -1s = 0 + -4
-1s = 0 + -4

Combine like terms: 0 + -4 = -4
-1s = -4

Divide each side by '-1'.
s = 4

Simplifying
s = 4
Solution
s = {13, 4}