You first see where it starts on the y axis. whether it be 1 or 2 or 3 or even 3. Than you look at the slope by counting from that point from the y axis going up and over until you reach a point. not a line a point. and if it's 3 up and one over than it's 3x. But it's for example it's 3 up and 2 over than it's 3/2x. Than you set up the equation as y= mx + b. m being the slope that you found. x just remains the same. and b is where the point started on the y axis