Question 167543
0.3x -0.2y =4    ...........(1)

0.4 x + 0.3 y = 73/19  ...........(2)

(1)  *  0.3  & (2) * 0.2

  0.3 x * 0.3 - 0.2y * 0.3 = 4 *0.3 
      0.09x  -0.06y = 1.2      .............(3)

   0.4x * 0.2 + 0.3 y * 0.2 = 73/19 * 0.2 

         0.08x + 0.06 y = 0.768  ..........(4)

(3) + (4)

        0.17x = 1.968

          x  = 1.968/0.17= 11.58

substituting x = 11.58 in (1)

        0. 3 * 11.58  -0.2 y = 4 
           3.474 -0.2y = 4 
                  - 0.2y = 4 - 3.474
                     - 0.2 y  = 0.526
                          y  = 0.526 / -0.2 
                             =  -2.63