00:01
So we see it takes 350 to drive 300 miles, and then in june it costs 524 miles to drive 880 miles.
00:13
We want to get the cost function, just assuming that it's linear.
00:17
So we have two ordered pairs here.
00:19
This is my cost for the number of miles.
00:22
So we want to know our cost.
00:24
So really what i need to do then is reverse these ordered pairs and say that 300 miles costs 350, and that 880 miles costs 524.
00:36
Because we want to know cost to be our dependent.
00:39
So i'm going to get y equals mx plus b.
00:42
So i'm going to go and i'm going to subtract and get 350 minus 524.
00:48
That's going to be negative 174.
00:50
And then 300 minus 880 is going to be negative 580.
00:56
So when i put those on top of each other as a fraction, i'm going to get .3.
01:02
So my slope is going to be .3.
01:05
So now i need to pick an ordered pair, and i'm going to pick this one...