3) a) 2/13(x)=52
15/13(x)=?
x=52:2*13
x=25*13
x=338
15/13(338)=2/13(338)+13/13(338)
15/13(338=52+338
15/13(338)=390
b) 2/7(x)=20
3/7(x)=?
x=20:2*7
x=10*7
x=70
3/7(70)=70:7*3
3/7(70)=10*3
3/7(70)=30
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4) 1 iepure=12 ani.
1iepure=6/7(oaie)...=> o oaie=12:6*7
o oaie=2*7
oaia=14 ani durata medie de viata a unei oi
5) a) 6/11(x)=12..=> x=12:6*11
x=2*11
x=22 cm
b) 4/7(x)=40...=> x=40:4*7
x=10*7
x=70 cm
