The perpendicular equation is y = 2x - 9.
You can find this by first realizing that perpendicular lines have opposite and reciprocal slopes. So since it starts at -1/2 we flip it and make it a negative and the new slope is 2. Now we can use that and the point to get the y intercept using slope intercept form.
y = mx + b
3 = (2)(6) + b
3 = 12 + b
-9 = b
And now we can use our new slope and new intercept to model the equation.
y = 2x - 9