Răspuns :
X+4Y+2+2Z=13,,,,3X+2Z=13,,,,,,,X+Y+Z=?
X+4Y+2+2Z+3X+2Z=13+13
4X+4Y+4Z+2=26
4X+4Y+4Z=26-2
4X+4Y+4Z=24
4(X+Y+Z)=24
X+Y+Z=24/4
X+Y+Z=6
X+4Y+2+2Z+3X+2Z=13+13
4X+4Y+4Z+2=26
4X+4Y+4Z=26-2
4X+4Y+4Z=24
4(X+Y+Z)=24
X+Y+Z=24/4
X+Y+Z=6