3/5 is your answer. Hope this helps. There’s a picture attached with the work.
A square has all of the same sides, so just do 12x12 which is 144
True if you think absolutely value 17 is 17 away from zero and 40 is 40
The x intercept is when y=0, in this case ax=c =>x=c/a
the y intercept is when x=0, in this case by=c =>y=c/b
the slope: by=-ax+c =>y=(-a/b)x+(c/b), so the slope is -a/b, the y intercept is c/b, which matches the answer in the second line.