Iago bought 2 cases of soda with 24 cans of soda in each case. on friday, he drank 3 sodas. on saturday, he had friends over and they drank all but 5 soda's. how many sodas did iago and his friends drink on saturday

There were 2 cases of soda, 24 in each. So 2•24=48. There were 48 total cans.
On Friday, he drank three of them. So there were 45 cans left.
On Saturday, there were 5 left. Since there were 45 cans before, 45-5 shows that Iago and his friends drank 40 sodas on Saturday.
[(2•24)-3]-5=40