Question

What do I do here?

Answer 1

so you want to find some value b that makes the line connecting P and Q parallel to the x-axis (in other words, the slope must be 0)

use the slope formula on the two points and set the slope equal to 0, then solve for b

Answer 2

actually, now that I think of it there's an easier method: since it's parallel to the x-axis, it's a horizontal line and thus the two points should have the same y-coordinate

Answer 3

oh -2

Answer 4

yep