Answer: 6 books = 15
11 books = 27.5
Step-by-step explanation: b = books
so we know that 8b = 20
so therefore we can say that 4b = 10
and 2b = 5
this means that one book costs $2.5
you can divide the total cost (20) by the books(8) to get the price
which is 2.5.
you can also just simply the equation 8b =20 by a factor 4
so you'd get 2b=5
from here you just divide both sides by 2
and you get 2.5$
NOW that we know b = 2.5.
set up an eqaution for 6 books and 11 books and solve
6(2.5)=x
11(2.5)=x