An artist spent $75 on supplies to create paintings.

Answer this 30 points and brainliest!

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

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?