Question 316321
I can see that we have a system of linear equations in two variables hidden in this travel application.

Let p = speed of plane

Let w = speed of wind

Objects traveling against the wind tend to slow down a bit and object traveling with the wind move faster.  Agree?  Try it on your bike on a windy day.

Against the wind:

time = 6 hours

speed = p - w

distance = 3960 km

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With the wind:

time = 5 hours

speed = p + w

distance = 3960 km


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From the tables above, we make the following equations:

6(p - w) = 3960
5(p + w) = 3960

6p - 6w = 3960...Equation A
5p + 5w = 3960...Equation B

Can you take it from here?

TIP: Use the substitution method to find p and w.