in plain and short, to graph an inequality, we first graph its EQUALITY graph, and then we do the shading.
so to graph y > x + 3, we first graph y = x + 3, which is just a line, and then do a true/false check on a point to see which side we shade.
let's hmmm check the point say (0,2), x = 0, y = 2.
y > x + 3
2 > 0 + 3
2 > 3 <--- is that true? is 2 really larger than 3? nope, so is false.
that simply means that the point (0, 2) is on the false area, so that's the area we do NOT shade, so we shade the other side.
y > x + 3, means "y" is greater than or larger than that line, but not equals, larger not equal, meaning the values on the borderline are not included, so the line is a dashed line.
check the picture below.
