You can put this solution on YOUR website! You want the equation either in standard form or in slope intercept form. Put into the form which you have the most comfort.
The slope plainly is . The slope for any line perpendicular will be the negative reciprocal, in this case, .
You can still stay with slope-intercept form, now wanting the equation perpendicular to .
Solve for b, and substitute the point which needs to be on the line, and then finish the equation.