Pageturner Bookstore sells two kinds of used books: hardcover and paperback. A hardcover book costs $8 and a paperback book costs $7. In one day, the store sold 10 books for a total of $76. How many hardcover books did they sell?

Step-by-step explanation:

Let h be hardcover and p be paperback

We have following equations:

Multiply the second equation by 7 and subtract from the first equation:

Let x be the number of hardcover and y be number of paperback

Then the equations are :---

Multiplying the second equation with 7 and substrating it from the first equation we get,

Therefore, bookstore sold 6 hardcover.