What is the rule for the function shown in the table?

input x -2 -1 0 1 2
output y -8 -5 -2 1 4

I'm so close to finishing all these.

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?

1: 4 if the wew 35 surfboards at the beach how many were short boards?