Răspunsuri

2014-06-17T18:27:43+03:00
F+b=120

f=20% din b=  20/100*b=  1/5 * b=  b/5

b/5 +b=120   aducem la acelasi numitor

b+5b=600
6b=600
b=100

f=120-100
f=20
2014-06-17T18:29:36+03:00
Notam cu f=femei
b=barbati
f+b=120

f=20% x b=  \frac{20 }{100}  \frac{1}{5} b

  \frac{b}{5} +b =120  
b+5b=600
6b=600
b=100

f= \frac{100}{5} =20