Question

the altitude of A (in feet) of a plane T minutes after liftoff is given by a=3400t + 600. How many minutes after liftoff is the plane at an altitude of 21,000 feet?

Answer 1

If our equation is
`a = 3400t + 600`, and we have a target altitude of
`21,000`, we just need to plug that in for
`a`.

`21,000 = 3,400t + 600`. Now subtract
`600` from both sides.

`20,400 = 3,400t`. now divide both sides by
`3,400`.

`6 = t`.

We get that our answer is at 6 minutes we get an altitude of 21,000 feet!