total distance travelled by the car (option D)
Step-by-step explanation:
When speed = 45mi/h
time = t hours
when speed = 65mi/h
time = m hours
45t +65m means 45mi/h × t + 65mi/h × m
The formula that relates the speed and the time is distance:
speed = distance/time
distance = speed × time
The distance for the first speed and time = 45mi/h × t hours = 45t
The distance for the second speed and time = 65mi/h × m hours = 65m
The sum of the two distance = distance covered by the car = 45t + 65m
Hence, we can say the expression 45t +65m represents the total distance travelled by the car (option D)