The slope of a vertical line is undefined, D.
If you were to try to solve use something like the rise over run method, you would end up with a 0 in the denominator. Since dividing by 0 gives you an undefined result, the slope would be undefined.
36 and 48
a = b+12
a+b = 84
(b+12) + b =84
2b +12 = 84
2b = 72
b= 36
a = b + 12
a = 36 + 12
a = 48
Travel at the speeds of 65 miles per hour to drive the distance of 310 miles (if the speed in which the person in question is traveling at the same speed) =
310 divided by 65 =
= 4 and

hours
since it is "traveled distance = speed multiplied by time it takes
X=4 because you combine 2+4 and subtract -6 then divide