1) x= nr camere cu 2 paturi
y= nr camere cu 3 paturi
x+ y=16 | ×2
2x+3y=42
2x+2y=32
2x+3y=42
_________
/ -y= -10 |×(-1)
y=10 camere cu 3 paturi
x=16-10
x=6 camere cu 2 paturi
2) x= varsta fiicei
y= varsta tatalui
y=x+26
y+4=3(x+4)
y=x+26 |×3
y+4=3x+12 |-4
3y=3x+78
y=3x+8
_________
2y= / 70 | ÷2
y=35 ani are tatal
35=x+26
x=35-26
x=9 ani are fiica