Răspuns :
f+b=137
f=b+23
________
f=?b=?
________
Inlocuim:
b+23+b=137
2b=137-23
2b=114
b=57
f=57+23
f=80
f=b+23
________
f=?b=?
________
Inlocuim:
b+23+b=137
2b=137-23
2b=114
b=57
f=57+23
f=80
notam cu f si b
f+b=137
b=f-23
inlocuim
f+f-23=137
2f=137+23=160
f=160:2
f=80
b=80-23
b=57
deci sunt 57 baieti si 80 fete
f+b=137
b=f-23
inlocuim
f+f-23=137
2f=137+23=160
f=160:2
f=80
b=80-23
b=57
deci sunt 57 baieti si 80 fete