1

Solve

\$ 7(3 - s/14)= -( - s - 10) \$

2

After simplification

\$ 21 - \cancel7^1s/\cancel(14)^2 = s + 10 \$

3

After cancelation

\$ 21 - s/2 = s + 10 \$

4

Move Variable terms to the left side and constant terms to the right side

\$ -s - s/2 = 10 - 21 \$

5

Taking LCM as '\$2\$'

\$ (-2s - s)/2 = -11 \$

6

After simplification

\$ (-3s)/2 = 11/1 \$

7

By using cross multiplication

\$ -3s = 22 \$

8

Dividing on both sides by '\$-3\$' of the equality

\$ \cancel(-3)^1/ \cancel(-3)^1 s = 22/(-3) \$

9

After cancelation

\$ s = - 22/3 \$

10

Answer

C = \$ s = - 22/3 \$