# A helicopter is 800 m above ground and descending at 55 m/min. An airplane is taking off and rising 80 m/min.

Question
A helicopter is 800 m above ground and descending at 55 m/min. An airplane is taking off and rising 80 m/min.

2021-02-10
Let h represent the height above the ground, in metres. Let t represent time, in minutes. h = 800 - 55t and h = 80t.
If h=80t, then by substitution method: 80t= 800- 55t
Simplified to: 135t=800
$$\displaystyle\frac{{800}}{{135}}$$ gives you: t=5.925
having the t value you can then put it into the "h=80t" equation as​ h=80(5.925), giving you: h= 474
To check mathematical accuracy, plug these answers back into the equation as 474= 800 -55(5.925) and 474= 80(5.925) Multiplying these out you would have balancing answers :)

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