Answer:
The Dairy Farm is better deal.
Step-by-step explanation:
Given that:
Per gallon charges of the Spotted Cow = $2.80
Delivery fee = $2
Let,
x be the gallons of milk.
S(x) = 2.80x + 2
Putting x = 20
S(20) = 2.80(20) + 2 = 56 + 2
S(20) = $58
Per gallon charges of the Dairy Farms = $2.10
Delivery fee = $10
D(x) = 2.10x + 10
Putting x = 20
D(20) = 2.10(20) + 10 = 42 + 10
D(20) = $52
Hence,
The Dairy Farm is better deal.