Hello there is solution : an equation for the line in point-slope form and general form is : y = ax+b a : slope ; the Passing through (x' ; y') y' = ax'+b y-y' =a(x-x') and : x' =1 y' =-7 calculate a : let : y = ax+b .....(D) x-2y-5 =0 .....(D') .(D) perpendicular to(D') : slope (D) × slope (D') = -1 but / x-2y-5 =0 .... 2y = x-5 y = (-1/2)x-5/2 slope (D') = -1/2 slop(D)×(-1/2) = -1 slope (D) = 2 equation for the line : y-y' =a(x-x') y+7 =2 (x-1) y = 2x-9