Answer:
The set of needed equations is 
h = 30 m 
11 m +  3  h = 909  where
 the driver drove for m hours.
 h : distance covered in m hours 
Step-by-step explanation:
Here, according to the question:
The per hour rate of driver  = $11
The gas maintenance expense = $3 per mile.
The total distance covered by drives is 30 miles per hour.
The total  expenses paid to driver  = $909
Now, let us assume the driver drove for m hours.
The average speed of driver was 30 miles / hour
⇒ Driver covers 30 miles in 1 hour
SO, distance covered in m hours  = h = m x 30 = 30 m
or, h = 30 m 
So,according to the question, the total amount paid :
Charges of m hours driving + maintenance charges for h miles
= 11 m + 3( h)
or, 11 m +  3  h = $909
Hence the set of needed equations is 
h = 30 m 
11 m +  3  h = 909