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:1,2,4,5, I just took the test
Step-by-step explanation:
Answer:
30×3=90 10×9=90 45×2=90 . .
Answer:
x = 2.5
Step-by-step explanation:
2x - 11 = -8x + 14
Add 8x to both sides
10x - 11 = 14
Add 11 to both sides
10x = 25
Divide both sides by 10
x = 2.5