Answer:
-1
Explanation;
The standard form of writing equation of a line is expressed as y = mx+b
m is the slope
b is the intercept
Given the equation x - y = 6
Rewrite in standard format
x - y = 6
-y = -x + 6
Multiply through by -1
y = x - 6
Compare with the standard equation
mx = 1x
m = 1
Note that the product of the slopes of two perpendicular lines is -1, hence;
Mm = -1
M is the required slope
M(1) = -1
M = -1/1
M = -1
Hence the slope of a line perpendicular to the line whose equation is x - y = 6 is -1