Passing through (3, 2) and (4, 7)
We use the slope formula to find the slope:
Slope formula:


where (x1,y1) = (3,2)
and where (x2,y2) = (4,7)








Point-slope formula:
y - y1 = m(x - x1)
where (x1,y1) = (3,2)
and slope = m = 5
y - 2 = 5(x - 3)
If you switch (x1,y1) and (x2,y2)
you get the other form.
Edwin