The quadrilateral formed by the lines y=ax+c, y=ax+d, y=bx+c and y=bx+d has area 18. The quadrilateral formed by the lines y=ax+c, y=ax−d, y=bx+c and y=bx−d has area 72. If a,b,c,d are positive integers then the least possible value of the sum a+b+c+d is

The quadrilateral formed by the lines y=ax+c, y=ax+d, y=bx+c and y=bx+

1.	The quadrilateral formed by the lines y=ax+c, y=ax+d, y=bx+c and y=bx+d has area 18. The quadrilateral formed by the lines y=ax+c, y=ax−d, y=bx+c and y=bx−d has area 72. If a,b,c,d are positive integers then the least possible value of the sum a+b+c+d is
Answer» The quadrilateral formed by the lines $y = a x + c$ , $y = a x + d$ , $y = b x + c$ and $y = b x + d$ has area $18$ . The quadrilateral formed by the lines $y = a x + c$ , $y = a x - d$ , $y = b x + c$ and $y = b x - d$ has area $72$ . If $a, b, c, d$ are positive integers then the least possible value of the sum $a + b + c + d$ is