notam cu x nucile oanei dupa ce ea si ioana ii dau nuci irinei
I_____I_____I irina=2*x
I_____I oana=x
I_____I____I ioana=x+40
2x+x+x+40=360
4x=360-40
4x=320
x=320/4
x=80
oana are 80 nuci
80+30=110
oana avea110 nuci
irina are 80*2 adica 160 nuci
irina avea 160-20-30 adica 110 nuci
ioana are 80+40 adica 120 nuci
ioana avea 120+20 adica 140 nuci