Explain why the equation is a linear function. then explain how to write an equation for the function.

It is a linear function.

Step-by-step explanation:

 It is a linear equation because it is in a straight line. The equation can be written in standard form as in y=mx+b, so it is a linear function. You can find an equation for this function by first picking a point on the line. I'd perfer to choose the line that goes through 3. As you know in the equation y=mx+b, the b in this equation is the y-intercept. Your line goes through 3. So the equation would be y=mx+3. Then you just need to find the slope by using the rise/run equation. Go down 3 times and 2 to the left. Your destination will then be the point on (0,-2). That is your rise over run. The equation then would be y= 3/2+3.