What is x^2 +2x+1 divides by x-4

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

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

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle