Add the Pasta and Salad first
8.60 + 3.50 = 12.10
Find the amount of the 2 lemonades by multiplying
1.05 x 2 = 2.10
Add
12.10 + 2.10 = 14.20
Add tax
14.20 + 1.15 = 15.35
Now subtract 20$ from the total of 15.35$
20.00 - 15.35 = 4.65
4.65$ is their amount of change