Answer:
-1
Explanation:
Using the slope-intercept form equation, you know that y=mx+b.
m is the slope of the line and b is the y intercept. The y intercept is where the point is when x=0. If you look at your equation and replace x with 0, you'll see that the y intercept (b) is 9.
You're looking for the slope of Line Q which is m in the equation. In this equation the slope is - 1.
Since Line R is supposed to be parallel to Line Q, then they must have the same slope. So both lines have a slope of - 1.