a/1/3 = 3a
2,(6) = (26-2)/9 = 24/9 = 8/3
2 1/3 = 7/3
3a = b/3 = 3c/8 = 3d/7
b = 3×3a = 9a
3c = 24a |:3
c = 8a
3d = 21a |:3
d = 7a
a + b + c + d = 25
inlocuim in functie de a
a + 9a + 8a + 7a = 25
25a = 25
a = 1
b = 9
c = 8
d = 7
v. 1 + 9 + 8 + 7 = 25
