Let the speed for the first 12 mi be x mi/h, the speed for 18 mi was (x+4) mi/h
thus given that
time=distance/speed
the average time will be:
3=(12+18)/(x+x+4)
3=30/(2x+4)
solving for x we get
3(2x+4)=30
6x+6=30
6x=24
x=4 mi/hr
Answer: 12 mi/hr
Answer:
62
Step-by-step explanation:
Answer:
I don't know sory.
Step-by-step explanation:
To solve for

You first need to find a common denominator.
To do so, you need to make both denominators 10 by multiplying the top and bottom of

by 5

=

Reduce by dividing both the top and bottom by 2
Your answer is