What is the slope of the line y = 3× + 9

Ineed the solution to this problem and the steps.

Becca wants to mix fruit juice and soda to make a punch. she can buy fruit juice for $3 a gallon and soda for $4 a gallon. if she wants to make 28 gallons of punch at a cost of $3.25 a gallon, how many gallons of fruit juice and how many gallons of soda should she buy?

Maryann’s friends loved her bulletin board, and 4 of them asked her to make one for their homes. she offered to make each of her friends a replica of her bulletin board that measures 2 meters by 3 meters. how many kilograms of burlap should maryann collect to complete the bulletin boards for her friends? maryann should collect kg of burlap.