Can anyone help ?

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

F(x) = 1/x g(x)=x-4 can you evaluate (g*f)(0) ? why or why not?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.