Find the value of x in each case. Give reasons to justify your solutions! please help will award brainliest

(40 points) i need some . an answer definition is appreciated as well.

There are 45 questions on your math exam. you answered 810 of them correctly. how many questions did you answer correctly?

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?