Answer:
she would save 1.1 extra gallons 
Explanation:
54 miles to work 
30 miles a gallon so 1.8 gallons to get to work 
27 miles a gallon so 2 gallons to get to work 
30 miles car saves 5.4 miles more each day she drives to work 
5.4 X 5 = 27 extra miles so 1.1 gallons she would be saving each work week