Answer :
Write each equation in y = mx + b form so that you can compare the slopes.
Perpendicular slopes are opposite reciprocals.
For example: 2/3 and - 3/2; 4/5 and -5/4; 1/2 and -2
I. y = -3x + 2 m = -3
II. y = 3/2 x + 1/2 m = 3/2
III. y = - 1/3x + 1/3 m = -1/3
IV. y = 1/3x + 9 m = 1/3 (I assuming this one had a typo in it since there is no equal sign.)
LETTER B is the answer I & IV
Perpendicular slopes are opposite reciprocals.
For example: 2/3 and - 3/2; 4/5 and -5/4; 1/2 and -2
I. y = -3x + 2 m = -3
II. y = 3/2 x + 1/2 m = 3/2
III. y = - 1/3x + 1/3 m = -1/3
IV. y = 1/3x + 9 m = 1/3 (I assuming this one had a typo in it since there is no equal sign.)
LETTER B is the answer I & IV