Question 142284
4x - 9y = 15 ...........(1)
3x - 4y = 14 ..........(2)
elimination by equating coefficient method, make coefficient of any of the variable same & equating for the other.

i.e coefficient of x made equal by 3 x (1)  & 4 x (2)

(1) x 3   
          4x * 3 - 9y * 3 = 15 *3 
               12x - 27 y = 45     ...............(3)
(2)x 4    
            3x * 4 - 4y *4 = 14* 4
               12x  - 16y  = 56   ................(4)

in eq: (3) & (4) coefficient of x are same , so eliminate it by subtracting (3) & (4)

        12x -27y = 45 ........(3)
        12x - 16y = 56 ...........(4)

(3) -(4)  
         0 - 11 y = -11 

      -11y = -11 

     y = -11 /- 11 
       = 1.

put y=1 in (1) & find x
   4x -9y = 15 
  4x - 9 *1 = 15 
   4x -9 = 15 
     4x= 15+9 = 24 
      x = 24/ 4 = 6 .