slope intercept form is: y=mx+b
so to find the slope select two points that are on the line than by the slope formula (y2-y1/x2-x1) find the slope. then to find b select one point from the line and substitute x and y with the values of your point then solve the equation and you will find the b. to finish, write y= (the slope that you found)x plus or minus (the b that you found)