First find the point-slope-form. Since you alreay have a point, all you need is the slope. Then use algebraic manipulation to obtain the slope-intercept form.Originally Posted byHayabusa

To find the slope, use the information that the new line should be the given one. How are the slopes of two perpendicular lines related?

OK, so you still need the slope of the given line. Use algebraic manipulation (solve the equation for y) to find this slope.

Hope this helps :-)