They are essentially asking us to solve:

Solving this equation for x tells us that it will take around 80.1 years for the materials in the vault to reduce to 357 pounds.
Answer:
10 x 10 x 10 x 10 x 10 = 100000
6 x 6 x 6 = 216
4 x 4 x 4 x 4 = 256
2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 1024 / or if the number was 21 x 0 then the answer = 1
Step-by-step explanation:
I already wrote the explanation in the answer but I'm guessing the number you put beside the first number is the exponent. So as you can see 73 = 7 mulitiplying by itself 3 times. The number 3 is an exponent because it tells you how many times you're multiplying the number by itself. If you continue doing that then you will get the same answer as I did. Good luck!
Answer:
I believe it would be -11/4.
The correct answer is "Draw a straight line from D to M". In order to draw a perpendicular line to line KDE you need to create two acrs that intersect above or below KDE. This is illustrated by the point M. This is the point that will create a perpendicular line and intersect KDE at a 90 degree angle.