A 13 -pound mixture of coffee that contains both decaffeinated and regular coffee costs $34. The decaffeinated coffee costs $2 per pound, and the regular coffee costs $3 per pound. (a) Let x be the weight of the decaffeinated coffee and y be the weight of the regular coffee. Write a system of equations whose solution gives the amount of each type of coffee in the mixture. (b) Use the method of substitution to solve the system of equations.

Question

Mathematics

Agustin Navarro

2 October, 09:44

A 13 -pound mixture of coffee that contains both decaffeinated and regular coffee costs $34. The decaffeinated coffee costs $2 per pound, and the regular coffee costs $3 per pound. (a) Let x be the weight of the decaffeinated coffee and y be the weight of the regular coffee. Write a system of equations whose solution gives the amount of each type of coffee in the mixture. (b) Use the method of substitution to solve the system of equations.

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Answers (1)

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Nina Montgomery · Answer 1

Weight of decaf coffee = 5 pounds.

Weight of regular coffee = 8 pounds.

Step-by-step explanation:

(a) Let x be the weight of decaf coffee and y the weight of regular coffee. Then:

x + y = 13

2x + 3y = 34

(b) From the first equation x = 13 - y, so substituting for x in second equation:

2 (13 - y) + 3y = 34

26 - 2y + 3y = 34

y = 34 - 26 = 8.

Substituting for y in the first equation:

x + 8 = 13

x = 5.