Find the vertex or else ill fail my class

Math                  way

Step-by-step explanation:

30

Step-by-step explanation:

Since the question says that it took her 45 minutes per hour, you can use that to find the distance of the route she took.  

45 miles: 60 minutes  

15 miles: 20 minutes cross multiply (20x45 and then divide by 60)  

Therefore, if she is going to use the same route in reverse, the distance would be 15 miles.  

Use the formula for speed:  

speed= distance/time  

= 15/0.5 0.5 hours is the same as 30 minutes  

= 30