Question

A grocer wants to mix two kinds of coffee. One kind sells for $0.85 per pound, and the other sells for $2.70

Answer 1

Answer:

x = $0.85 per pound = 19.85 pounds

y = $2.70 per pound = 1.14 pounds

Step-by-step explanation:

Let

x = $0.85 per pound

y = $2.70 per pound

x + y = 21 (1)

0.85x + 2.70y = 19.95 (2)

From (1)

x = 21 - y

Substitute x = 21 - y into (2)

0.85x + 2.70y = 19.95 (2)

0.85(21 - y) + 2.70y = 19.95

17.85 - 0.85y + 2.70y = 19.95

- 0.85y + 2.70y = 19.95 - 17.85

1.85y = 2.1

y = 2.1 / 1.85

y = 1.14

Substitute y = 1.14 into (2)

0.85x + 2.70y = 19.95

0.85x + 2.70(1.14) = 19.95

0.85x + 3.078 = 19.95

0.85x = 19.95 - 3.078

0.85x = 16.872

x = 16.872 / 0.85

x = 19.85

x = $0.85 per pound = 19.85 pounds

y = $2.70 per pound = 1.14 pounds