To be perpendicular to x = 4, the line must be y = something. This eliminates answer choices #2 and #4. Also, to pass through the point (.5, 7), the line must be y = 7.
So answer choice #3.
Hope this helps!! Let me know if you have ANY questions.
Step-by-step explanation: Add 42mph and 54 mph and you get 96. To find the average of the two --- divide 96 by 2 and you get 48mph as the average speed for the entire trip.