Answer:
-1/3
Explanation:
the slope of this line
m=(y1-y2)/(x1-x2)
m=(7-(-2))/(2-(-1))
m=9/3=3 --> slope of the first line
in order to find the slope of the line that is perpendicular to this one we need to find the reciprocal of this (their products need to be equal to -1)
so the slope of the second line is (-1/3)