The equation is put in slope intercept form which is y=mx+b
The slope is m and in this case it is -1/2.
To find the y intercept substitute in 0
for x then solve.

Let the third side = x.
The sum of any two sides must be greater than the third side
14 + 9 > x
23 > x
14 + x > 9
x > -5
9 + x > 14
x > 5
So 5 < x < 23
The final number of outcomes would end up being 10 possible outcomes because you would do five and multiply it by two. And there would be a possibility of landing on any of ten outcomes. Hope I helped reassure you of your answer :)
At the same rate Teresa would drive 567mi.
756/12 = 63
63 x 9 = 567