Two planes

Two planes are flying from airports A and B, 420 km distant from each other. The plane from A took off 15 minutes later and flew at an average speed of 40 km/h higher than the plane from B. Determine the average speed of these two aircraft if you know that it will meet 30 minutes after takeoff A.

Correct answer:

a =  360 km/h
b =  320 km/h

Step-by-step explanation:


a=b+40
a·30/60 + b· (45/60)=420

a-b = 40
30a+45b = 25200

Pivot: Row 1 ↔ Row 2
30a+45b = 25200
a-b = 40

Row 2 - 1/30 · Row 1 → Row 2
30a+45b = 25200
-2.5b = -800


b = -800/-2.5 = 320
a = 25200-45b/30 = 25200-45 · 320/30 = 360

a = 360
b = 320

Our linear equations calculator calculates it.



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Showing 1 comment:
Technoblade
this is good.

1 year ago  1 Like




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