Whoever needs it, stay strong king/queen <3 (free points btw :)

What are the soultion(s) to the quadratic equation 40- x^2=0

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?

Ihave trouble finding the nth term of a linear sequence