The equations of four lines are given. Identify which lines are perpendicular. HELP PLEASE!! The answer with the red arrow is wrong!

Only lines 2 and 4 are perpendicular. We know that perpendicular lines intersect and form four 90° angles. [tex]y - 1 = 4(x - 3)[/tex] is simply the inverse of [tex]\frac{1}{4}x + 1[/tex]