when 2 lines are perpendicular its slopes are inverted and have a different sign
so, the slope of the given equation is -1/2 and the perpendicular is

now to write the new equation we start from the general equation of the line

where m is the slope and b the y-intercept
we replace the slope on the equation and the given point to find b

now replacing b and m we can find the equation of the perpendicular line
