Answer:
6 minutes
Step-by-step explanation:
'a' in the formula represents altitude in feet. You are told the altitude is 21000 feet, so put that into the formula:
21000 = 3400t +600
You can solve this for t:
20400 = 3400t . . . . . subtract 600 from both sides
6 = t . . . . . . . . . . . . . . . divide both sides by 3400
The problem statement tells you that t represents minutes after lift off, so this solution means the altitude is 21000 feet 6 minutes after lift off.
The question is asking for the number of minutes after lift off that the plane reaches an altitude of 21000 feet, so this answers the question directly:
The plane is at an altitude of 21000 feet 6 minutes after lift off.
Answer:

Step-by-step explanation:
Use the Pythagorean theorem. 
a and b are the two side lengths
c is the hypotenuse (value across from the right angle)
Plug in the values that you are given.

Solve for x


x=

Answer:
Step-by-step explanation:
Let C be the total charge and t be the rental time in hours.
C = ht + 43
Plugging the given values into the equation, we get:
64 = 7h + 43
7h = 21
h = 3
The hourly fee is $3.00 per hour.
72 hours I hope this helps