Which statement best describes the function h(t) = 210 – 15t?

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?

Prove that 16^4-2^13-4^5 is divisible by 11.

Can someone show me step by step how to do this?