Răspunsuri

2014-11-18T18:37:25+02:00
1)C3+r=C4
2)C4+r=C5
din 1 si 2=> C3+2r=C5
C5-C3=2r
2r=6
r=3
C2=C3-r=4
C9=C5+4r=25
C15=C9+6r=43