How do u identify slope

Is -24 a solution to the equation -16+2x=-64

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?

For the equations below which statement is true ? -2x=14 6x=-42