Janelle tracks the number of miles she drives and the number of gallons of gas she has left. what is the linear regression model for this scenario?

If you graph this scenario, the number of gallons of gas left will be on the y-axis while the number of miles traveled will be on the x-axis.

The line will be going downwards as the miles get longer. This is because the number of gallons of gas left will decrease as Janelle drives farther. 

Assuming that Janelle initially had 10 gallons of gas and 1 mile consumes 1 gallon.

x   y
0  10                          As you can see, if you graph these coordinates,
1   9                           the line of best fit will be going downwards. 
2   8
3   7
4   6
5   5
6   4
7   3
8   2
9   1
10  0

2/1 or just 2. sorry if i get this wrong