Question

At a music store, compact discs cost $14.95 each, but are now on sale for $12.95 each. If you bought ten compact discs in the past month, and spent a total of $139.50, how many did you buy on sale?

Answer 1

5 compact discs on sale.

Step-by-step explanation:

To solve this you'll need to set up a system of equations. Let's use x or the original price and y for sale price. Here's what your equations will look like:

14.95x + 12.95y = 139.50

x + y = 10

Now, cancel out x so you can solve for y. You can choose either variable, but canceling out x gets you to your answer in less steps. Remember to multiply by a negative so you can cancel out the variable.

Here's what your work will look like:

14.95 + 12.95y = 139.50

-14.95 (x + y = 10)

Here's what your new equations will look like after distributing:

14.95x + 12.95y = 139.50

-14.95x - 14.95y = -149.5

Now, add these two equations together. When you do that, x cancels out and you can solve for y.

Here's what your new equation will look like after adding:

-2y = -10

Now, divide both sides by -2. After doing so, you should get y = 5. This means that you bought 5 compact discs on sale.

Hope this helps!

Answer 2

To determine the number of compact discs bought on sale, we need to calculate the difference between the total spent and the total cost at the original price. However, the calculations provided result in a negative value, suggesting an error or missing information in the question.

Step-by-step explanation:

To determine how many compact discs were bought on sale, we need to calculate the total cost of the ten CDs bought in the past month. We know that the total spent is $139.50 and that the original price of each CD was $14.95. To find the number of CDs bought on sale, we subtract the total cost spent at the original price from the total spent.

First, we calculate the total cost spent at the original price: $14.95 x 10 = $149.50.

Next, we subtract this amount from the total spent: $139.50 - $149.50 = -$10.00.

Since we have a negative result, it means that a mistake has been made in the calculations or there might be some missing information in the question.