410 is your answer, 2 subtractions signs next to eachother make a plus sign, so in the end it’s just 356+54 :)
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:
origin dilation if 5. is 5
ok done. Thank to me :>