Well if you have a standar form equation you have to change it to thic equation y-y1=m(x-x1) you do this by plugging in the points or lope in the correct order. For example if you had y=4x+3 the 4 would be plug in for m now we have to find x1and y1 we do that by finding a point for example you get a graph and plug in the 3 and rise 4 over one this is positive so it would give you a point of (1,7) so so now plug in the x1 and the y1 your slope form equation should be y-7=4(x-1)
Hope this helps