C.supplementary is the right one
Answer:
-1
Step-by-step explanation:
Step-by-step explanation:
By the formula of slope, we have

Answer:
the answer is 
Step-by-step explanation:
You have to find the common denominator in order to get the sum.
multiply 5 to
and you get 
then to double check the sum, subtract it.

hope this make sense :/
The order does not matter (A,B,C same as B,C,A) so it's a combination 28 choose 5.