Răspunsuri

2014-06-17T14:44:41+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

a=120-100
a=20
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2014-06-17T14:45:59+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}

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

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