2[s+3(s-1)]=18

Solution for 2[s+3(s-1)]=18 equation:

Simplifying
2[s + 3(s + -1)] = 18

Reorder the terms:
2[s + 3(-1 + s)] = 18
2[s + (-1 * 3 + s * 3)] = 18
2[s + (-3 + 3s)] = 18

Reorder the terms:
2[-3 + s + 3s] = 18

Combine like terms: s + 3s = 4s
2[-3 + 4s] = 18
[-3 * 2 + 4s * 2] = 18
[-6 + 8s] = 18

Solving
-6 + 8s = 18

Solving for variable 's'.

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

Add '6' to each side of the equation.
-6 + 6 + 8s = 18 + 6

Combine like terms: -6 + 6 = 0
0 + 8s = 18 + 6
8s = 18 + 6

Combine like terms: 18 + 6 = 24
8s = 24

Divide each side by '8'.
s = 3

Simplifying
s = 3