Answer:
the cost of 7 roses and 8 petunlas is $41
Explanation:
Bethany sells roses and petunias. the cost expression is given by

where r represents the number of roses and p represents the number of petunlas
Given : 7 roses and 8 petunlas
r=7 and p=8
Plug in the values in the given expression and find out the total cost


41
the cost of 7 roses and 8 petunlas is $41