I think the original price is either $51 or $69
Answer:
you have to do it yourself
Since it is perpendicular to y=3x-1, the slope must be a negative reciprocal.
there the slope of the perpendicular line is

So now we have,

To find b, we use the point that the line passes through and substitute it to the y and x values.

which would give us b=5/3
Therefore, the equation of the line is
Since x can be any value as long as the denominator equals 0 (it doesn't matter if it's positive or negative), we have to figure out when x^2=0, which is when x=0. Therefore, the domain is (-inf, 0) U (0, inf)