Răspuns :

 2x +5y = 13 ·(-4) 
 8x -9y = -25

⇒ -8x- 20y= -52
    8x-9y= -25, se aduna cele doua relatii 
-----------------------------------------------------------
     /   -29y= -77⇒ y= 77/29 
  2x +  385/ 29 = 13, se aduce la numitor comun (29)
58x+385= 377
58x= 377- 385
58x= -8
x= -8/58
x= -4/29 

2x +5y = 13 | ·(-4) 8x -9y = -25 ⇒ -8x- 20y= -52 8x-9y= -25, se aduna cele doua relatii ----------------------------------------------------------- / -29y= -77⇒ y= 77/29 2x + 385/ 29 = 13, se aduce la numitor comun (29) 58x+385= 377 58x= 377- 385 58x= -8 x= -8/58 x= -4/29