Răspuns :
a+c=x
a=60%din x
c=80
80=40%
80......40%
y.........100%
y=100*80/40=8000/40=200 lei andrei
x=200+80=280 lei costa cadoul
a=60%din x
c=80
80=40%
80......40%
y.........100%
y=100*80/40=8000/40=200 lei andrei
x=200+80=280 lei costa cadoul
[tex]...................
60 din x = 60/100*x=6/10*x=3/5*x = 3/5x andrei
x-3x/5= (5x-3x)/5= 2x/5 -restul
2x/5=80
x=5*80/2
x=5*40
x=200 lei andrei
x=200+80
x=280 lei costa cadoul[/tex]