y=x+2 will be a positive upwards graph that has a slope of 1 this means it will cross diagonally perfectly it won't change directions and it won't go up more than down or left more than right. It will cross the x axis at 2.
y=-x+2 It will be the same thing but this time starts from the top left and goes down gets to x axis at positive 2 again
y=|x|+2 This will go down from top left again and hit positive 2 on y axis then go back up making a v it does not curve and it does have a perfect slope of 1 making it easy to graph.