Not sure if the symbol is a minus or plus sign, but regardless, just solve for y in terms of x to have the form y = mx + b. A line perpendicular to it will have a slope that is the negative reciprocal of your line.
So, say the line you gave (I'm assuming) is 3x - 2y = 34. The slope "m" is y = mx + b = (3x - 34)/2 = 3/2*x - 17, so slope = 3/2. Perpendicular line will have slope that is negative reciprocal, so it will be -1 / (3/2) = -2/3. so y = mx + b, so y = (-2/3)x + b. We know it passes through the point (0,0), so your y-intercept is 0.
The line should be y = -(2/3)x.