Help please im really confused if u help)

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8

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?

Which of the following expressions cannot be simplified to x – 2?