You can't, at least in the sense that you cannot write the equation of any line. That is because there are an infinite number of ways to express an equation of any line. What you can do is write an equation of a line.
First we know that perpendicular lines have slopes that are negative reciprocals, which is to say:
The equation of the given line is presented in slope-intercept form, namely . Hence we can determine the slope of the given line simply by inspection of the coefficient on . Take this number an calculate the negative reciprocal.
Take the slope number you just calculated and the coordinates of the origin, to wit: , and then use the two point form of an equation of a line:
where are the coordinates of the given point and is the calculated slope. Put the result into whatever form your instructor expects your answers to take.
John
My calculator said it, I believe it, that settles it
