Answer:
-9/2
Explanation:
To make a slope perpendicular, you must find the slope in a y = mx+b format where the slope is easy to find. Add 2x to the opposite side and then divide the entire right side of the equation by 9 to get y = 2/9x +8/9. A perpendicular slope is just a negative reciprocal of the slope, so make 2/9 negative and flip around the numerator and denominator to get a perpendicular slope of -9/2. Hope that helps!