Answer:
22 cars & 2 trucks
Explanation:
Let c stand for cars
Let t stand trucks
12c + 18t = 300
If we know that c is 22, then let's find t:
12(22) + 18t = 300 (first do what is in parenthesis)
264 + 18t = 300 (then combine like terms)
18t = 36 (divide to get t alone)
t = 2
Ans: They washed 22 cars and 2 trucks