28=s(s-3)

Solution for 28=s(s-3) equation:

Simplifying
28 = s(s + -3)

Reorder the terms:
28 = s(-3 + s)
28 = (-3 * s + s * s)
28 = (-3s + s2)

Solving
28 = -3s + s2

Solving for variable 's'.

Reorder the terms:
28 + 3s + -1s2 = -3s + 3s + s2 + -1s2

Combine like terms: -3s + 3s = 0
28 + 3s + -1s2 = 0 + s2 + -1s2
28 + 3s + -1s2 = s2 + -1s2

Combine like terms: s2 + -1s2 = 0
28 + 3s + -1s2 = 0

Factor a trinomial.
(7 + -1s)(4 + s) = 0

Subproblem 1
Set the factor '(7 + -1s)' equal to zero and attempt to solve:

Simplifying
7 + -1s = 0

Solving
7 + -1s = 0

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

Add '-7' to each side of the equation.
7 + -7 + -1s = 0 + -7

Combine like terms: 7 + -7 = 0
0 + -1s = 0 + -7
-1s = 0 + -7

Combine like terms: 0 + -7 = -7
-1s = -7

Divide each side by '-1'.
s = 7

Simplifying
s = 7
Subproblem 2
Set the factor '(4 + s)' equal to zero and attempt to solve:

Simplifying
4 + s = 0

Solving
4 + s = 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 + s = 0 + -4

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

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

Simplifying
s = -4
Solution
s = {7, -4}