# Rachel needs to write 3 book reports with b pages and 3 science reports with s pages during the school year. How do you write an algebraic expression for the total number of pages Rachel will need to write?

Nov 30, 2017

$3 b + 3 s$

#### Explanation:

We have $3$ books each with $b$ amount of pages. We can write this as $b + b + b$ or $3 b$ as we have $3$ lots of $b$ pages.

Now looking at the number of science reports, we have 3 lots of s pages, so it is $3 s$.

Working out the total number of pages we add the number of book reports and the number of science reports, so we end up with $3 b + 3 s$

Hope this helps!