Bravo. A little laborious to get to (7a - 6) (7b - 5) = 30. Since we operate in Z, we must also try ( -1)(-30), (-2)(-15) ... but this does not give integers for a and b.
Why olways so complicated solution for primitive "problems"? 5 is prime number so _a_ can be either 1 or 5. 6 has three dividers 1, 2 and 3. Next is primitive strait forward and obvious.
Bravo. A little laborious to get to (7a - 6) (7b - 5) = 30.
Since we operate in Z, we must also try ( -1)(-30), (-2)(-15) ... but this does not give integers for a and b.
We operate on Z+
Why olways so complicated solution for primitive "problems"?
5 is prime number so _a_ can be either 1 or 5.
6 has three dividers 1, 2 and 3.
Next is primitive strait forward and obvious.
Although your No. 4 results are noninteger and therefore rejected, the actual results you obtained are wrong. Check carefully. Dr. Ajit Thakur (USA).