There were 287 music books and 134 science books in the store. After some books were sold there are 159 books left. How many books were sold?

262 books sold

Step-by-step explanation:

This is a very vague word problem, but if it truly is just asking the amount of books sold (regardless of music or science), here's how to get the answer:

1. 287+134=421 - first you want to add together the two types of books to get the total amount of books in the store

2. 421-x=159 - create an equation and solve.

3. - x=-262 - follow order of operations and subtract 421 on both sides in order to isolate the variable

4. x=262 - divide each side by - 1 to make the variable positive.

If you'd like an easier way, you can just:

1. 421-159=262 - it's easier, but my math teacher would count us wrong if we didn't do equations a specific way. Good luck!

There were 262 books sold.