Answer:
5
Step-by-step explanation:
You solve the equation
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:
c
Step-by-step explanation:
It would be 20 percent, I believe. First you would put it into a fraction of 12\60, then you would simplify that into 3\15 then divide as shown. You end up with .2 which would be 20 percent.
Answer:
your answer is correct.
Step-by-step explanation:
For the purpose here, we'll call the missing point on the arc through Z point X.
Essentially, you want to make ΔXYZ ≅ ΔLMN by SSS. The construction so far ensures LM ≅ MN ≅ XY ≅ YZ. By copying the length LN to XZ, you ensure the congruence of the remaining sides of the triangles.
Then ∠XYZ ≅ ∠LMN because corresponding parts of congruent triangles are congruent.
In short, XZ needs to be the same distance as LN.