Question

Daca segmentul AB cu lungimea de 48 cm,se imparte in parti direct proportionale cu numerele 5 si 7 ,atunci cele doua segmente au lungimile de ?

Answer 1

A l..........O..............B
AO/OB=5/7
Prin derivare obtinem:
(AO+OB)/OB=(5+7)/7    Dar AO+OB=48  ⇒
48/OB=12/7
OB×12=48×7
OB=48×7/12   Simplificam  cu 12
OB=4×7
OB=28 (cm)
AO=48-28
AO=20 (cm)