I need help mathematically

I'm confused on this could anyone me and show me what i need to do to solve it.

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?

What rule describes a dilation with a scale factor of 4 and the center of dilation at the origin?