Răspuns :

notam pasarile cu p si oile cu o
o+p=120 => o=120-p
2p+4o=298 => 2p+4(120-p)=298
2p+480-4p=298
-2p=-182
p=91 => o=29
x-nr oi
y-nr pasari

x+y=120 |-2
4x+2y=298

-2x-2y=-240
4x+2y=298
.................
2x/ =58
x=29
y=91