Solve.The function A = A0e-0.0077x models the amount in poun…

Solve.The function A = A0e-0.0077x models the amount in pounds of a particular radioactive material stored in a concrete vault, where x is the number of years since the material was put into the vault. If 300 pounds of the material are initially put into the vault, how many pounds will be left after 30 years?