sophia has 8 books in her locker. all the books are either school books or personal books. she has three times as many school books than personal books. how many school books does sophia have in her locker?

Question

zepdrix · Answer

Let S represent the number of School books she has in her locker.
Let P represent the number of Personal books she has.

They told us that she has THREE TIMES as many School books as Personal books. We can represent that like this,
3S=P
This equates 3 school books to each personal book.

zepdrix · Answer

The total number of books in her locker is 8.
We can write that like this,$$\large S+P=8$$This equation is telling us - some number (S) of School books PLUS some number (P) of Personal books, totals 8.