(-1,5) slope=2
y-y1=m(x-x1)
y-5=2[x- (-1)]
y=2x +7
also if you start at point (-1,5) and apply the slope of 2/1
then up 2 and over 1 would give you (0,7) then you can use y=mx+b
where b is the Y value when x is 0 and m is the slope
