Answer:
0.80c + 12 ≤ 28.40
c ≤ 20.5
Step-by-step explanation:
c represents # of cups of coffee
0.80 is the price per cup of coffee
so in the inequality it's 0.80c
$12 is how much the mug costs so it's + 12
for solving the inequality isolate c :
0.80c + 12 ≤ 28.40
0.80c ≤ 16.4
c ≤ 20.5
so this means that charlie can buy 20.5 cups of coffee and a $12 mug and the total won't exceed the $$ on his coffee stop card
