x=suma frate 1
y=suma frate 2
z=suma frate 3
x+y+z=130
x-2/3x=y-75%y=z-40%z
x-2/3x=y-3y/4=z-2z/5
x/3=y/4=3z/5
x=3y/4
z=5y/8
3y/4+y+5y/12=130
9y+12y+5y=1560
26y=1560
y=60 lei
x=3*60/4=45 lei
z=5*60/12=25 lei
45*2/3=30 lei a cheltuit fratele 1
60*45%=45 lei a cheltuit fratele 2
25*40%=10 lei a cheltuit fratele 3