My soccer team has 16 players. I have to choose a starting lineup of a goalie and 10 regular players (the regular players are interchangeable). How many different starting lineups can I choose?

Let's say that the unknown value here is c. Although we are given two points on the line, it is only necessary to use one as there is only one unknown value, so let's say we choose the point (6, -12) and substitute this into the equation:

-12 = 1(6) - c
-12 - 6 = -c
-18 = -c
c = 18

Thus the equation for the line is y = 1x - 18