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John and Ariana bought school supplies. John spent $11.00 on 5 notebooks and 7 pens. Ariana spent $7.00 on 4 notebooks and 2 pens. What is the cost of 1 notebook and what is the cost of 1 pen?

Respuesta :

Step-by-step explanation:

set notebooks as x, set pens as y

1. 5x + 7y = 11

2. 4x + 2y = 7

1.  times by 2

10x + 14y = 22

2. times by 7

28x + 14y = 49

2. minus 1.

18x = 27

x = 1.5

sub 1.5 into 2.

4(1.5) +2y = 7

6+2y = 7

2y = 1

y = 0.5

Therefore, x = 1.5, y = 0.5

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