I'm just going to link a picture to the question in my book since I have no idea how I would even attempt to draw a graph on here manually.

Basically, I don't understand why in the equation "y = -2/3x - 3" when they go to plot it on the graph, they're making the -3 a positive 3 instead, and there are other parts in the book that have a similar equation where both the slope and the y intercept are negatives, but they use both as positives when turning it into the graph portion, and I really don't understand why.

Any help would be much appreciated in understanding why that is.

mathproblem_zpsa6456c35.png Photo by Azuraiiii | Photobucket