Two coplanar lines that are perpendicular to the same line are parallel

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?

Find the distance between c and d on the number line c=3 and d=11

Which equation represents h for right triangle abc