Răspunsuri

2014-09-24T12:12:59+03:00
F-fete
b- baieti
f+b=28
f=40%xb
40%xb+b=28 simplificam 40%
2/5xb+b=28 aducem la acelasi numitor
2xb+5xb=28x5
7b=140
b=140/7
b=20
f+20=28
f=28-20
f=8