Answer:
He can buy no more than 3 gallons
Step-by-step explanation:
Let c = cookies and m = milk
1.5c + 6m
This is how much he is going to spend
it must be less than or equal to 30
1.5c + 6m≤ 30
He is going to buy 8 cookies
1.5*8 + 6m≤ 30
12 + 6m ≤ 30
Subtract 12 from each side
12+6m -12 ≤ 30-12
6m ≤ 18
Divide by 6
6m/6 ≤ 18/6
m≤ 3
