2. _MA_ = _3_ 1. Transformări: 1 dm =? cm
AB 5 =10 cm
MB=1 dm I______?______I____10 ___I
_______________ A M B
AB= ? cm I___________?___________I
_MA_ = _3_ ⇒ 5·MA= 3·AB
AB 5 5·MA=3·(MA+ MB)
5·MA=3·MA+ 3·MB
5MA-3MA= 3MB
2MA= 3MB
2MA= 3·10 I :2
MA= 3·5
MA=15 cm
AB=AM+MB
AB= 15+10
AB= 25 cm
35 mm
3. [AB]=35 mm I____________I_________I
P ∈ (AB)
_PA_ = _4_ A P B
PB 3
________________
[PA]= ? , [PB]= ?
_PA_ = _4_ ⇒3PA=4PB AB= PA+ PB
PB 3 PA= _4PB_ AB= _4PB_ + PB
3 3
3AB=4PB+ 3PB
3AB= 7 AB
3·35= 7·PB I : 7
3·5= PB
15 mm =PB
PA= _4PB_
3
PA=_4·15_
3
PA= 4·5
PA=20 mm
