To find the perpendicular slope of a line, just reciprocate its slope, and for finding the line parallel to it, according to purplemath.com:
"In numbers, if the one line's slope is m = 4/5, then the perpendicular line's slope will be m = –5/4. If the one line's slope is m = –2, then the perpendicular line's slope will be m =1/2. To answer this question, I'll find the slopes. Since these two lines have identical slopes, then these lines are parallel."
I hope my answer has come to your help. God bless and have a nice day ahead!