Răspuns :
x-barbati
y-femei
x+y=120 //prima formula
x=20y/100 //a 2-a formula
x=y/5
y/5+y=120|(*5) //inloucim in prima formula
6y/5=600|:5
6y=120
y=20 femei
x=120-30=100 barbati
y-femei
x+y=120 //prima formula
x=20y/100 //a 2-a formula
x=y/5
y/5+y=120|(*5) //inloucim in prima formula
6y/5=600|:5
6y=120
y=20 femei
x=120-30=100 barbati
a+b=120
a-nr.femeilor
b-nr.barbatilor
a=20b/100 simplificam =b/5
b/5+b=120 aducem la acelasi numitor
(b+5b)/5=120
6b/5=120
b=120x5/6
b=100
a=b/5=100/5=20
nr.barbatilor 100
a-nr.femeilor
b-nr.barbatilor
a=20b/100 simplificam =b/5
b/5+b=120 aducem la acelasi numitor
(b+5b)/5=120
6b/5=120
b=120x5/6
b=100
a=b/5=100/5=20
nr.barbatilor 100