Step-by-step explanation:
Distance = Speed * Time
If Maria drove to a business appointment at 30 mph, then
d = 30t where d is her distance and t is the time
If her average speed on the return trip in the afternoon was 20 mph and the return trip took 1/2 hr longer, then;
her speed s = 20mph
her time t1 = 1/2 + t
distance d = 20(1/2+t)
Since the distance both going and returnin are the same then:
30t = 20(1/2 + t)
3/2 t = 1/2 + t
3/2 t - t = 1/2
1/2 t = 1/2
t = 1 hr
Substitute t = 1hr into the first equation to get the distance
d = 30t
d = 30(1)
d = 30miles
Hence she travelled 30 miles to the appointment
