0.7 (3s+4) - 1.1s = 7.9
1. First, you have to multiply everything within the parenthesis by 0.7.
0.7*3s = 2.1s & 0.7*4 = 2.8
2.1s + 2.8 - 1.1s = 7.9
2. Then, you subtract 2.8 from both sides.
7.9 -2.8 = 5.1
2.1s -1.1s = 5.1
3. Combine like terms. In this case, the like terms are the variables.
2.1s-1.1s = 1s
s = 5.1
