Answer:
1/2
Step-by-step explanation:
there is a total of 12 people
6/12 people have red hair
if you simplify, it is 1/2
therefore there would be a 1/2 chance that someone with red hair would be chosen.
The answer would be 0.0049088359
to get the equation of any straight line, we simply need two points off of it, let's use those two points in the picture below.

keeping in mind that for the point-slope form, either point will do, in this case we used the second one, but the first one would have worked just the same.
Answer:
-(20+z)/y = x
Step-by-step explanation:
-20=xy +z
Subtract z from each side
-20 -z = xy+z-z
-20 -z = xy
Divide each side by y
(-20 -z)/y = xy/y
Factor out a negative
-(20+z)/y = x