we have that
points A (2,2) and B (4,8)
we know
the equation in point-slope form of the line is
y-y1=m*(x-x1)
step 1
find the slope m
m=(y2-y1)/(x2-x1)=(8-2)/(4-2)=6/2=3
with the point A (2,2) and m=3
y-2=3*(x-2)------------> this is the equation in point-slope form of the line