Answer: 20. 4, 3, 2, 1...
21. 17....
Step-by-step explanation:
This is an impossible equation. If sqrt(x) = sqrt(x), and sqrt(x) + 2 = sqrt(x) + 12, then that would mean that 2=12, which is incorrect.
The expression is (15+6) */* 3. This is because we add up all the costs to get the total, and divide the total by three because there are three friends splitting the cost.
