Write an expression for: add 2 and 4 and multiply the sum by 3.* show work*

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?

Can some one explain this i got sent this. is this a threat i’m scared

What is the value of the discrimination for the quadratic equation 0=×2+2+×2