What inverse operation should be used to isolate the variable in the equation k − 9 = 10?

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?

The graph below represents the number of dolphins in a dolphin sanctuary. select all the key features of this function.

Can someone me out here and the tell me the greatest common factor