Let
y-------> number of books read during the month 
x------> number of picture of a book
we know that

in this problem
for 
calculate y

therefore
the answer is
The number of books read during the month
is 
Answer:
Tha answer of this question is an angle
Answer: |-10| < |11|
So choice C. is right.
hope this helps!
Given cos theta is equal to - 4/ 7 then we can conclude that theta is in the second and third quadrants. In this case, the other leg is equal to square root of (7^2 - 4^2 ) equal to square root of 33. In this case, sin theta can be equal to +- square root of 33 / 7 and tan theta is equal to +-square root of 33 / 4.