-x^3 + x^2/3 + 5 - 13/x
I don't know if this is correct
If you meant to write y=23x-4 then none of the lines are perpendicular.
I suspect you intended y=2/3x-4, then line D, y=-3/2x-4 is perpendicular.
For any line y=mx+b, you have to "invert" m to get a perpendicular line. Inverting in this case means: flip numerator and denominator and add a minus sign.
So 2/3 becomes -3/2, hence answer D.
The 'inverted' m is called the opposite reciprocal. That's your word of the day.
