Hello! i need on this, i really don’t understand it. so much!

If m 17 27 90 63 ** picture is attached

Write the fraction or mixed number and the decimal shown by the model

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?