A line perpendicular to y=2/3x+9 would be y=-3/2x+k where k is any constant.
The slope of y=2/3x+9 is 2/3.
The negative reciprocal of 2/3 is -3/2.
y=-3/2x+k where k is a constant.
k can be any constant, such as 2, 5, or even 65.
y=-3/2x+k would be the answer.
