Răspuns:
gabriela are 18 nuci
mara are 15 nuci
bianca are 22 nuci
Explicație pas cu pas:
notam :
cu M mara
cu B bianca
cu G gabriela
M+B=37 nuci
B+G=40 nuci
M+G=33 nuci
M=? ; G=? ; B=?
M=37-B
B=40-G
inlocuim in M+G=33 nuci
37-(40-G)+G=33 nuci
desfacem paranteza : 37-40+G+G=33 nuci
-3+2G=33 nuci.... adunam 3
2G=36 nuci .... impartim cu 2
G=18 nuci => gabriela are 18 nuci
M+G=33
M+18=33 => M=33-18 => M=15 .......=> mara are 15 nuci
M+B=37 nuci
15+B=37
B=37-15=22 => bianca are 22 nuci