(0,0) and (-4,-5) in point slope form ( show work if possible)

I think formula is y2-y1 divided by x2-x1 so if im correct
-5/-4

Givens:
point slope form: y-y1=m(x-x1) 
need to find slope "m" 
x1=0, y1=0, x2=-4, y2=-5

m= (y2-y1)/ (x2-x1)= (-5-0)/(-4-0)= -5/-4=5/4
than just substitute for either point
y-0=5/4(x-0)
or
y+5=5/4(x+4)