Răspuns:
2x+3y=23
5y+8z = 97
a) 5y+8z-(2x+3y)=97-23
5y+8z-2x-3y=74
2y+8z-2x=74
b) 2x+3y=23 I·2=>4x+6y=46
5y+8z=97 I·3 =>15y+24z=291
4x+6y+15y+24z=46+291
4x+21y+24z=337
c) 2x+3y=23 I·4 =>8x+12y=92
5y+8z=97 I ·9 => 45y+72z=873
45y+72z -(8x+12y)=873-92
45y+72z-8x-12y=781
33y+72z-8x=781
d) 2x+3y=23 I·5 => 10x+15y=115
5y+8z=97 I·7 => 35y+56z=679
10x+15y+35y+56z=115+679
10x+50y+56z=794