first you need to find the slope of he current equation by changing it to y=mx+b
3x-2y=9 subtract 3x from both sides
-2y=-3x+9 divide both sides by -2
y+3/2x-9/2 Your slope of the existing is 3/2 or 1 1/2
a perpendicular line has the opposite reciprocal slope so 3/2 would be -2/3
-3 is your y intercept. now you can make your equation
y=-2/3x-3
