x+y+z=130
2/3 din x= 75% din y= 40% din z
2x/3= 75/100 *y= 40/100 *z
2x/3= 3y/4= 10/25 *z
2x/3 =3y/4 = 2x/5 aducem la acelasi numitor
40x = 45y= 24z
x=45y/40
z=45y/24
45y/40 + y+ 45y/24= 130 aducem la acelasi numitor
1080y + 960y + 1800y= 124 800
3 840y= 124 800
y=32,5
x= 45* 32,5/40= 1462,5/40= 36,56
y= 45*32,5/24= 1462,5/ 24= 60,93
b)2/3 din 36,56= 2/3 *36,56= 2*12,186=24,37 lei a cheltuit primul
3* 32,5/4= 3*8,125= 24,375 lei a cheltuit al doilea
2* 60,93/5= 2*12,186 lei a cheltuit al treilea