Which rational function models the time, y, in hours, that it takes the train to travel between the two cities at an average speed of x miles per hour?

y= x/6.4
y= x/160
y= 6.4/x
y= 160/x

Step-by-step explanation:

The complete question in the attached figure

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form or

In this problem, we have a proportional relationship between the average speed (x) and the time (y)

Find the constant of proportionality k

Fox =32, y=5

substitute

we have

therefore

y=160/x

Step-by-step explanation:

other answer is wrong. i just did this question

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)