1/2 - 2/15= 15-4/30 = 11/30 this means that if you were to add 11/30 to 2/15 is exactly equal to 1/2, to fully answer your question you can use any value above that like 12/30 (keep in mind you have to simplify) = 6/15 = 2/5. But then again your question says to add any number to make it greater than 1/2 so technically you could just add 100 or 200 or 1/2 to make the sum of it greater than one half
Answer:
x - 11
Step-by-step explanation:
- A number stands for an unknown variable in which x takes it place
- The word fewer alerts us to subtraction, thus the minus sign
- 11 fewer than a number is the same as saying a number minus 11.
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.