# I Diophantine equation

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1. Oct 9, 2016

### Ling Min Hao

The given question required me to solve 7x+4y =100 by using diophantine equation . I get an answer for x = 100 - 4t and y = 200 - 7t . But his given answer is x = 4t and y = 25-7t . I think both of mine and the answer given is correct but I can't figure out how he get another solution

2. Oct 9, 2016

### Staff: Mentor

What values can t have?

3. Oct 9, 2016

### mathman

4. Oct 10, 2016

### Staff: Mentor

I think you mean -7x+4y=100.

5. Oct 10, 2016

### mathman

You are right - my typo.

6. Oct 11, 2016

### Ling Min Hao

Both answer is correct since both can be used to find the value of x and y , it's just I don't understand how he get the answer using dio phantine method

7. Oct 11, 2016

### mathman

I am not familiar with the Diophantine method. However, by substituting your answer into the original equation, it is obviously wrong. His answer is obviously correct. I can only guess you are misusing the Diophantine method.