The slope is negative one
I don’t understand your question
September : 12
october: 18
november : 16
together in sept. and oct. = 12+18 = 30
number of books he read more in sept. and oct. then just nov.= 30 - 16 = 14
in short, the answer is 14 books.
hope it helps you!
Answer:
(3 + 4 + 5 + 7 + 10 + 12 + 15)/7 = 8
(3^2 + 4^2 + 5^2 + 7^2 + 10^2 + 12^2 + 15^2)/7 - 8^2 = 17.14285714