First find the slope of the line given by changing it into slope intercept form.
0.5x-5y=9
-5y=-0.5x+9
y=0.1x-9/5
The slope is 0.1
To find a perpendicular slope, find the negative reciprocal.
The reciprocal of 0.1 is 10
The negative of 10 is -10
Final answer: -10
