Answer:
B
Explanation:
X=Amount of hours you drive (70mph)
Y= Amoumt of hours your friend drives (75mph)
X+Y has to be equal to or less than 10 (X+Y=or<10)
You want to drive 500 miles or more in 10 hours or less at an average speed of 70mph for you and 75mph for your friend.(70X+75Y=or<500)
So overall....
X+Y=or<10
70X+75Y=or>500
(Both X and Y can be equal to zero or greater)