2(20-s)+s-3=30

Solution for 2(20-s)+s-3=30 equation:

Simplifying
2(20 + -1s) + s + -3 = 30
(20 * 2 + -1s * 2) + s + -3 = 30
(40 + -2s) + s + -3 = 30

Reorder the terms:
40 + -3 + -2s + s = 30

Combine like terms: 40 + -3 = 37
37 + -2s + s = 30

Combine like terms: -2s + s = -1s
37 + -1s = 30

Solving
37 + -1s = 30

Solving for variable 's'.

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

Add '-37' to each side of the equation.
37 + -37 + -1s = 30 + -37

Combine like terms: 37 + -37 = 0
0 + -1s = 30 + -37
-1s = 30 + -37

Combine like terms: 30 + -37 = -7
-1s = -7

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

Simplifying
s = 7