Pls explain me these 2 questions

If you could answer these your a life saver

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) 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 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?

The amount of data left on the cell phone six gb for 81.5 gb of data is used how much data is available at the beginning of the cycle