<span>the straight line passes through the point (2,1) and is vertical
x=2 (vertical), so we can have the value of B and C, x-2=0 so B=0 and C=-2 the main equation is x - 2 = 0
</span><span>inear equation Ax+By+C=0 of the straight line that passes through the point (-2,3) and is horizontal. y=3, (horizontal) y-3=0, so A=0, B=1 and C=-3 the main equation is y-3=0</span>
