Question

Answer to question below

Answer 1

13n+20

Explanation:

Each book costs $13 with a flat rate of $20

You pay $13 for each book, which will be n. And aside from that you also pay for shipping, which will be another $20

So the correct answer is: 13n+20

Answer 2

what is the flat rate for shipping? it would be 13n and then + or - the number given (flat rate for shipping)
hope this helped :)