179k views
5 votes
At a grocery store, 7 apples and 2 oranges will cost $12.80. In addition, 6 apples and 3

oranges cost $12.00. Assuming that we are talking about the same apples and oranges, what is the
cost of 1 apple? What is the cost of 1 orange? Let x represent the cost of an apple
and y represent the cost of an orange. Show ALL work!
Equation #1:
Equation #2:
Cost of 1 apple: $
Cost of 1 orange: $

1 Answer

8 votes

Answer:

Equation 1: 7x + 2y = 12.8

Equation 2: 6x + 3y = 12

Cost of 1 apple: $1.60

Cost of 1 orange: $0.80

Cost of 1 orange: $Step-by-step explanation:

Let's use the elimination method to solve this

Multiply equation 1 by 3

(7x + 2y = 12.8) x 3 = 21x + 6y = 38.4

Multiply equation 2 by -2

(6x + 3y = 12) x -2 = -12x - 6y = -24

The x terms will cancel each other out

21x + 6y = 38.4

-12x - 6y = -24

9x = 14.4

Divide by sides by 9 to isolate the x variable

9x/9 = 14.4/9

x = 1.6

This means an apple costs $1.60

Plug the new x into one of the original equations to find y; we'll use equation 1

7(1.6) + 2y = 12.8

11.2 + 2y = 12.8

Subtract 11.2 from both sides

11.2 + 2y = 12.8

- 11.2 - 11.2

2y = 1.6

Divide both sides by 2

2y/2 = 1.6/2

y = 0.8

This means an orange costs $0.80

User Hiyasat
by
4.9k points