MCQ
Which pair of lines are perpendicular?
Unit-8 Geometry of Straight Lines
A 3x + 4y = 12 and 4x - 3y = 5
B 3x + 4y = 12 and 6x + 8y = 24
C 2x + 3y = 6 and 4x + 6y = 12
D x + y = 2 and x + y = 4
Explanation

Their slopes are -3/4 and 4/3, and (-3/4) * (4/3) = -1.