For this case, the first thing you should do is use the distance between points formula. We have then: d = root ((x2-x1) ^ 2 + (y2-y1) ^ 2) Substituting we have: d = root ((9 - (- 9)) ^ 2 + (-2-7) ^ 2) d = 20.1246118 Rounding off we have: d = 20 units Answer: The distance, to the nearest unit, between your house and the subway stop is: B. 20