In one afternoon, Brian sold 25% of his chocolate bars. If he had 72 bars left, how many chocolate bars did he have to begin with?

6.3x+14 and 1.5x-6 answer in simplified form

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

Which graph represents the equation y =4x