Since it is perpendicular to y=3x-1, the slope must be a negative reciprocal.
there the slope of the perpendicular line is [tex] -\frac{1}{3} x[/tex]
So now we have,
[tex]y=- \frac{1}{3} x+b[/tex]
To find b, we use the point that the line passes through and substitute it to the y and x values.
[tex]2=- \frac{1}{3} (-1)+b[/tex]
which would give us b=5/3
Therefore, the equation of the line is
[tex]y=- \frac{1}{3} x+ \frac{5}{3} [/tex]