Question

PLEASE HELP CHECK A PROBLEM

Answer 1

I call with (v) the speed of the plane in still air, and with (w) the speed of the wind

Answer 2

now, when the wind is behind the plane, then the speed of the plane with respect to the still air is:
v+w

Answer 3

so the time for the trip is:
t=1980/(v+w)= 4.5 hours

Answer 4

@freckles

Answer 5

when the wind is in front of the plane, then the speed of the plane with respect to the still air is v-w, so the time for the trip is:
t=1980/(v-w)=5.5 hours

Answer 6

what's the problem are you not getting it @wade123

Answer 7

hint:
now we can write the subsequent equations:
\[\Large \begin{gathered}
\frac{{5.5}}{{4.5}} = \frac{{v + w}}{{v - w}} \hfill \\
\\

\left( {v + w} \right) \times 4.5 + \left( {v - w} \right) \times 5.5 = 2 \times 1980 \hfill \\
\end{gathered} \]

Answer 8

the first equation is from the ratio between the two times,
and the second equation is from the total space travele by the plane
from the first city to the second city plus the distance from the second city to the first city