The sum of 14 and a number is equal to 17

Which graph represents the following piecewise defined function?

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

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?