Question

Swiss cheese and Limburger cheese cost different amounts per pound, but you do not know how much. A box containing 3 pounds of Swiss and 2 pounds of limburger costs 24.40 dollar. Another box containing 4 pounds of Swiss and 5 pounds of Limburger costs 47.70 dollars. Assuming that these figures are for the cheese only (not for the box), how much does the Swiss cheese cost per pound?

Answer 1

3S + 2L = 24.40

4S + 5L = 47.70

Multiply the first equation by 5 and the second by 2.

15S + 10L = 122

8S + 10L = 95.40

Subtract the second equation from the first.

7S = 26.60

Divide both sides by 7.

Answer 2

If the costs are L and S, then we are told that

3S+2L = 24.40
4S+5L = 47.70
or,
15S+10L = 122.00
8S+10L = 95.40
subtract and you get
7S = 26.60
S = 3.80

This seems for comfortable than direct substitution.

3S+2L = 24.40, so
L = 12.20 - 1.5S

4S+5L = 47.70
4S+5(12.20-1.5S) = 47.70
-3.5S = -13.30
S = 3.80

Answer 3

guig