oi-x vitei-y<br />x+y=65 ×=65-y<br />3x+2y=180<br />inlocuim in ecuatia 2 pe x cu 65-y si rezulta ca:<br />3(65-y)+2y=180<br />195-3y +2y=180<br />195-180=3y-2y<br />15=y sau y=15<br />x=65-15<br />x=50<br />R: 50 de oi si 15 vitei
nr.fete-x nr.baieti-y
x+y=1350
x=y/2-30 inlocuim in ecuatie pe x cu:
y/2-30+y=1350
y/2+y=1350+30
3y/2=1380 y= (1380×2)/3
y=920
x=1350-920
x=430
