First, you must change the second one into slope-intercept form.
3x+y=2 subtract 3x from both sides and get y= - 3x +2.
when finding a perpendicular slope, you find the inverse of the original slope. first, you flip the fraction (adding a /1 if it isn't one) then switch the sign (multiply by -1) thus, -3x is the inverse of 1/3x, so it is perpendicular.
