Hello!
To graph this, you will want to create two points based off of the equation. You plug an x-value into the equation, and you put the y-value outcome with it as an ordered pair. You do this twice, giving you two points to connect.
For example, let's plug in an x-value 1, giving us (1,y)
y= 1-3 (We remove the absolute value)
y=-2 (Subtract)
This gives us one point, (1,-2)
Let's try using -2 as another point.
y= 2-3 (Remove absolute value)
y= -1 (Subtract)
This gives us the point (-2,-1)
To graph, you would draw a straight line through the points (1,-2) and (-2,-1). Note you could do this with any x-value and you would get the same line.
I hope this helps!