Find the distance between the points (10,5) and (6,2)

Part a: select all of the ordered pairs that are located on the graph of the equation. part b: does the graph of the equation represent a function? select all correct answers for part a and one answer for part b.

Apatient is to take 60 mg of an antibiotic on day 1, take 45mg on days 2 and 3, take 30mg on days 4 and 5 and take 15 mg on days 6 and 7. how many total mg will the patient take?

How do you use the elimination method for this question? explain, because i really want to understand!