The line joining the points A ->(1,0) and B->(2,3) is divided at C in the ratio 1:3. So the coordinates of C will be. ((1×3+2×1)/4,(0×3+3×1))/4)
=(5/4,3/4)
The slope of AB = (3-0)/(2-1)=3
The slope of the line perpendicular to AB will be -1/3
Hence the equation of the line passing through C and perpendicular to AB will be
(y-3/4)-1/3(x-5/4)
=>-12x+15=4y-3
=>12x+4y-18=0