notam raportul molar 121Sb:123Sb=x:y
Arelativ=(n1*A1+n2*A2)/(n1+n2)
121,855=(121x+123y)/(x+y)
121,855x+121,855y=121x+123y
0,855x=1,145y => x=1,333y
x+y.................100%
x........................a%
y........................b%
a=1,333y*100/2,333y=57,14% 121Sb
b=1*100/2,333y=42,85% 123Sb