Step-by-step explanation: First we want to find the total amount of cola Trey bought. Each pack contains 8 cans, so multiply 18 packs by 8 cans to find the total amount of cans he bought. 18 x 8 = 144 total cans of cola.
Since Trey drank 7 of the cans, simply subtract 7 from 144, 144 - 7 = 137 total cans of cola remaining.