It is really a good idea to borrow another sheep; But if there is no borrowed sheep, is there no way to solve this problem? Actually, it is not. It is very simple to answer this question with the knowledge of proportional distribution in primary school mathematics.

Method 1:

17 sheep, the eldest son gets 1/2, the second son gets 1/3, and the third son gets 1/9, that is, 17 sheep share1/2:1/. Therefore:

9+6+2= 17

The eldest son gets: 17× 9/ 17 = 9.

Second son: 17× 6/ 17 = 6.

Share of the third son: 17× 2/ 17 = 2.

Solving this problem with equations is equally simple.

Method 2: According to the problem, the boss collected 17/2 cows, the second 17/3 cows and the third 17/9 cows.

Then the second child is 2/3 of the boss and the third child is 2/9 of the boss.

Suppose the boss receives X cows, then the second child receives 2/3x cows and the third child receives 2/9x cows.

x+2/3x+2/9x= 17

x=9

So the boss collected 9 cows, the second one collected 6 cows and the third one collected 2 cows.