Find a slope of a line parallel to 3x minus y equals 1

3x - y = 1

First you have to change this into slope intercept form (y = mx + b).

3x - y = 1

-y = - 3x + 1

y = 3x - 1

m = 3

(m is the slope)

So the line parallel to this line will also have a slope of 3.

If they waned the perpendicular line though, it would be the negative reciprocal (-1/3).

The answer is 3.