I will make you the brainliest if RIGHT

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

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?

Aquadrilateral has exactly one pair of parallel sides. which name best describes the figure?