S = 105
z = 1/3 x - 9
y = x+9
x+y+z = 105
x+x+9+1/3x-9=105
2x+1/3 x = 105 ( amplifam 2x cu 3 )
7/3x = 105
x = 105 / [tex] \frac{7}{3} [/tex] ==> x = 105 × [tex] \frac{3}{7} [/tex] ==> x = 315/7 ==> x = 45
y= 45+9 = 54
z = 1/3 × 45 - 9 ==> z = 15 -9 = 6
R :
z = gaste = 6
y = gaini = 54
x = rate = 45