Answer:
Explanation:
Since all cards have the same price, there is a direct relation between the number of cards and the cost, with the unit price being the constant of proportionality.
The unit price is determined from the point (4, 10), whihc means 4 cards for $10.
Point (6,15) means that 6 cards cost $15. Is that true?
Use the constant of proportionality:
Hence, indeed the cost of 6 cards is $15, and that is represented by the point (6, 15).