Answer: Slope of 1.
Explanation:
First, we will put the equation into slope-intercept form.
x - y = 4
x = y + 4
y = x - 4
Our slope, when the line is written as y = mx + b, is the m value. Our m value here is one, so the slope of a line parallel to the line whose equation is x - y = 4 is 1.