Solve the given system by graphing.
x + y = -6
x-y=2

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.

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

Choose the linear inequality that describes the graph. the gray area represents the shaded region. a: y ≤ –4x – 2 b: y > –4x – 2 c: y ≥ –4x – 2 d: y < 4x – 2