Final answer:
The ordered pair representing the cost of 3 sketchbooks and the cost of 3 puzzles is (3, 9), where 3 sketchbooks cost $3 (x-value) and 3 puzzles cost $9 (y-value).
Step-by-step explanation:
The question involves determining the costs associated with a certain number of items at fixed prices, a common problem in algebra and mathematics-related to equations of lines or financial math. Mrs. Beatty purchases both sketchbooks and puzzles, with each sketchbook costing $1 and each puzzle costing $3. She buys 3 of each, so to find the total cost for each type of item, we would multiply the price of the individual item by the quantity purchased.
The cost for 3 sketchbooks would be calculated as 3 sketchbooks × $1 per sketchbook = $3. Similarly, the cost for 3 puzzles would be calculated as 3 puzzles × $3 per puzzle = $9. Therefore, the ordered pair that represents the cost of 3 sketchbooks and the cost of 3 puzzles is (3, 9).
The x-value in this ordered pair represents the cost of the sketchbooks and the y-value represents the cost of the puzzles. This sort of problem is foundational to understanding how linear equations work, such as the example equation y = 25 + 15x, which expresses the total earnings as a fixed fee plus a variable fee per hour.