Ascientist has 50 g of radioactive element. the amount of radioactive element after t days can be determined using the equation f(f)=50(1/2)^t/5. after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is f(f)=50(1/2)^t-2/5. which of the following is an equivalent form of the expression for the amount remaining in shipment 2?