Using number lines 80 is 25% of what number

Why did the ice arena get so hot after the big game (this is math related google it to find the paper

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2

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?