at a used book sale each paperback book cost x dollars and each hardcover book cost y dollars.

Question

One customer purchased 7 paperback books and 5 hardcover books and paid $10.80
Another customer paid $9.45 and purchased 3 paperback books and 6 hardcover books
What system of equations can be used to find the cost of 1 paperback book and the cost of 1 hardcover book?

Answer 1

Let's define:
x = cost of 1 paperback book
y = cost of 1 hardcover book

From the given information, we can form the following equations:

First equation:
7x + 5y = 10.80

Second equation:
3x + 6y = 9.45

So, the system of equations that can be used to find the cost of 1 paperback book and the cost of 1 hardcover book is:

7x + 5y = 10.80
3x + 6y = 9.45