Which is greater to less then 9.129,9.37,9.3,9.219

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.

Ineed with angles and the measure of them i have abc a is 65 and b is (3x-10) and c is (2x) find the value of x

Plz hurry evaluate the expression a+b where a=8 and b=19