Answer:
3
Step-by-step explanation:
Since there is no increase in height, we will look at the horizontal distance.
We can compare the distance from (0,0) to (5,0) and (15,0)
Distance from (0,0) to (5,0) = 5 units
(0,0) to (15,0) = 15 units
So, k is the ratio of the new distance over the original: k = 15/5 --> k = 3
