Basic Definitions in exercises 1-8, use the diagram. Don’t just give answers please explain it out for me.

Which ahows the graph of the solution set of 6x+4y< 12

Tamera puts 15/4 gallons of gasoline in her car. which mixed number represents the gallons of gasoline? a) 2 3/4 gallons b) 3 1/4 gallons c) 3 3/4 gallons d) 4 1/2 gallons answer it's worth a lot of points!

Anyone know? is appreciated! will mark brainliest if correct!