2 ms·
The 3c^4 ≡ 6 (mod 15) line is missing parentheses... As written, it means 3 * (c^4) ≡ 6 (mod 15), which is demonstrably false (e.g. 3 * (4^4) = 768 ≡ 3 (mod 15)
by MauranKilom 6y ago
The 3c^4 ≡ 6 (mod 15) line is missing parentheses... As written, it means 3 * (c^4) ≡ 6 (mod 15), which is demonstrably false (e.g. 3 * (4^4) = 768 ≡ 3 (mod 15)).
- ersatz_username 6y agoYou’ve got a factor of three sneaking into your 4^4. In general (ab) mod n == (a mod n)(b mod n) mod n In the case of (3*c)^4, 3^4 mod 15 -> 108 mod 15 -> 3.