Select the pair of equations whose graphs are perpendicular.
(Points : 5)
a 5x – 8y = 9
12x – 5y = 7
b x + 6y = 8
y = 2x – 8
c y = 2x – 7
x + 2y = 3
d 2y = –3x + 5
2x + 3y = 4
i think it d im i correct