PLZ HELP BRAINLIEST, THIS IS A PROOF IN GEOMETRY

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?

Carmen ayer en el mercado compro 3/4 kg de guayabas, 6/8 kg de peras, 1/2 kg de naranjas ¿cuantos kilogramos de fruta compro?

Which value of y will make the inequality y< -1 false?