What is 984757847573 / 3=

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 verbal translation for the difference of m and 7 increased by 15

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?