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.
D. It Is The Most Fitting Answer. The Other 3 Equal More Than Needed.
Okay, since quotient is the answer to a division problem, you will divide w and -8. Increased means to add so, you will +7.
w/-8 +7 is what the expression looks like.
6 packs of 3
2 packs of 9
3 packs of 3, 1 pack of 9
answer: 3 ways
There is 273 thousands. Remember, take out your zeros. Hope it helps! :)