Answer:
I'm sorry, I don't know if I know this but you should try Desmos if you haven't already. It's great for helping with slopes and stuff like this
when running a line, in a right-triangle, from the 90° angle perpendicular to its opposite side, we will end up with three similar triangles, one Small, one Medium and a containing Large one. Check the picture below.

Answer:
10
Step-by-step explanation:
A suitable matrix calculation tells you
(x, y, z) = (-8, -1, -3).
4%of 500 = 20
500 plus or minus 20 gives range as (480,520)