How do i solve this least or greatest decimal

Taber invested money in an account where interest is compounded every year.he made no withdrawals or deposits. the function a(t)=525(1+0.05)^t represent the amount of money in the account after t years. how much money did taber origanally invested?

Deena is planting two rectangular gardens. one garden is 3.67 feet by 8.56 feet, and the other garden is 3.67 feet by 7.45 feet. which expression does not respresent the total area in square feet of the two gardens

P= price tax is 4% added to the price. which expression shows the total price including tax?