Can someone pls help me​

Asequence is defined recursively by the formula  f(n  +  1)  =  f(n)  +  3 . the first term of the sequence is  –4. what is the next term in the sequence? –7–117

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.

Which inequalities can be used to find the solution set of the following inequality? check all that apply. |2x – 5| (2x – 5) (2x + 5) –(2x – 5) –(2x + 5)