9a+6s

find the total cost for 4 adults and 4 students

The total is $56.

you have to plug in the numbers into the expression. the a would be replaced by 4 (4 adults). the s would be replaced by 4 (4 students).

the numbers already in the expression (9 and 6), are the costs of 1 adult and 1 student, respectively. multiply by the number of adults and students.

9a+6s

9 (4) + 6 (4)

32 + 24

56