Answer:
It is the total cost of housing and plane tickets for four years.
Explanation:
Mark's costs for tuition, technology fee, and books are all per semester, s. ($2,600 + $150 + $310)s = $,060s
The cost for housing and plane tickets are a once a year cost. Mark pays these amounts once a year for four years.4($5,600 + $289) = $23,556
Therefore, the constant in the expression is $23,556, and it is the total cost for housing and plane tickets for four years.