It's

because this choice made the most since.
Forty two plus sixty three that's your answer
the slope is -6/5. This is because it goes down 6, and then to the right for 5. You can also use the slope formula to solve this.
The answer is f when 2,3 is put in for the x and y then 18 should come out 3×2=6
4×3=12 12+6=18