100-80-4s=s

Solution for 100-80-4s=s equation:

Simplifying
100 + -80 + -4s = s

Combine like terms: 100 + -80 = 20
20 + -4s = s

Solving
20 + -4s = s

Solving for variable 's'.

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

Add '-1s' to each side of the equation.
20 + -4s + -1s = s + -1s

Combine like terms: -4s + -1s = -5s
20 + -5s = s + -1s

Combine like terms: s + -1s = 0
20 + -5s = 0

Add '-20' to each side of the equation.
20 + -20 + -5s = 0 + -20

Combine like terms: 20 + -20 = 0
0 + -5s = 0 + -20
-5s = 0 + -20

Combine like terms: 0 + -20 = -20
-5s = -20

Divide each side by '-5'.
s = 4

Simplifying
s = 4