The answer is B six books, hope this helps!
I'll go slow:





Answer: B rational and equal to 0.
Answer: the total of the tip is 2 dollars
it also depends for how many people
Step-by-step explanation:
The equation for this is a^2+b^2=c^2 so your equation would be 7^2+20^2=X
So you square the 7 and the 20 then take the square root of X and you get
X=21.19
:)