2b+15
2 dollars for each book so you multiply it by the number of books and add 15 because it is a one time fee.
For A B and C, you just plug in the given number
A

B

C

And for D, you set the equation to 26 and solve for n

I had to use x instead of n, but for D n=7. :)
Answer:
510.1
Step-by-step explanation:
convert m to km by dividing by 1000 and add all of the numbers together
Its 157, because 180-23= 157 degrees.