Question

Ioana,Malina si Ana cantaresc impreuna 165 kg. ioana cantareste o data si jumatate cat malina , iar Malina cantareste o data si un sfert cat ana. cate kg are fiecare?

Answer 1

I+M+A=165 kg
I=M+M:2 /×2
2I=2M+M
2I=3M
I =3M/2
M=A+A:4 /×4
4M=4A+A
4M=5A
A=4M/5
inlocuim in prima ecuatie i functie de M
3M/2+M+4M/5=165 /×10
15M+10M+8M=1650
33M=1650
M=50 kg (Malina)
I =3×50/2=3×25=75 kg (Ioana)
A=4×50/5=4×10=40 kg (Ana)

verificare
50+75+40=165 kg