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:
-6 and -3
Step-by-step explanation:
1.3
5.51
8.2
7.5
2.5
4.12
2.25
3.25
5.12
7.30
thats all i know