If 19 out of 28 renters keep a pet, there are
renters who don't keep a pet.
Whenever you have a subset of some set, and you want to know which percentage of the set the subset represents, you simply have to compute

So, in your case, you're wondering what percentage of 28 does 9 represent. So, the formula becomes

Substitute the value for y as 450
450=-5x+1
Solve for x
450-1=-5x
449=-5x
89.8=-x
x=-89.8
Take two points
Slope
Parallel lines so slopes are equal
Only y intercept will vary
So both lines have y intercept at -3 and -1 respectively
The equations
Put (0,0) on first one
On second one
So as lines are dashed symbols remain >
The inequalities are