What is the slope of a line that is perpendicular to the line represented by the equation x - y = 8?

First write the equation of the line in y = mx + b form.

x - y = 8
-y = -x + 8
y = x - 8

Now we know that the slope of the perpendicular line is opposite and reciprocal.

Slope of the given line = 1

Slope of the perpendicular line = -1

Hope this helps :)