Răspuns :
x-y=23
x+y-(x-y)=12
x+y-23=12
x+y=35
x-y=23 x=23+y x=23+y x=23+6 x=29
x+y=35 y+23+y=35 2y=12 y=6 y=6
x+y-(x-y)=12
x+y-23=12
x+y=35
x-y=23 x=23+y x=23+y x=23+6 x=29
x+y=35 y+23+y=35 2y=12 y=6 y=6