Answer:
r = 225 Mil/h speed of the airplane in still air
Step-by-step explanation:
Then:
d is traveled distance and r the speed of the airplane in still air
so the first equation is for a 4 hours trip
as d = v*t
d = 4 * ( r + 25) (1) the speed of tail wind (25 mil/h)
Second equation the trip back in 5 hours
d = 5 * ( r - 25 ) (2)
So we got a system of two equation and two unknown variables d and
r
We solve it by subtitution
from equation (1) d = 4r + 100
plugging in equation 2
4r + 100 = 5r - 125 ⇒ -r = -225 ⇒ r = 225 Mil/h
And distance is :
d = 4*r + 100 ⇒ d = 4 * ( 225) + 100
d = 900 + 100
d = 1000 miles
Rachel spends 6 hours 45 minutes a week trying to learn to play the violin.
Step-by-step explanation:
Step 1; Rachel learns for 45 minutes a day from Monday through Friday and in the weekend she learns to play the violin for one and a half hours. So she learns for the following periods of time
Monday - 45 minutes
Tuesday - 45 minutes
Wednesday - 45 minutes
Thursday - 45 minutes
Friday - 45 minutes
Saturday - 90 minutes (60 × 1.5 hours)
Sunday - 90 minutes (60 × 1.5 hours)
Step 2; To determine how much time she practices in a week we just add the individual times she plays on each day.
Total time practices in a week = 45 + 45 + 45 + 45 + 45 + 90 + 90 = 405 minutes = 6 hours 45 minutes.
Answer: Option D
Step-by-step explanation:
The y-axis of the table represents the range of the function.