If 10 pencils and 7 erasers cost $4.23 and 3 pencils and 1 eraser cost $0.95, what is the cost of 2 erasers?

Answer: $0.58

Step-by-step explanation:

Let x represent pencil and y represent eraser

10x + 7y = 4.23 → 1 (10x + 7y = 4.23) → 10x + 7y = 4.23

3x + y = 0.95 → - 3 (3x + y = 0.95) → - 21x - 7y = - 6.65

-11x = - 2.42

:-11 : -11

x = 0.22

3x + y = 0.95

3 (0.22) + y = 0.95

0.66 + y = 0.95

y = 0.29

2y = 2 (0.29) = 0.58