AE575DRTQ ỨAE65U5W
29/10/2017 at 09:08-
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1.
Because p and q are prime number > 3
=> q can equal 3k+1 or 3k+2
But if q = 3k+1 => p = 3k+1 + 2 = 3k+3 divided by 3 -> wrong
And if q = 3k+2 => p = 3k+2 + 2 = 3k+4 divided by 3 remainder 1 -> right
So p+q = 3k+2 + 3k+4 = 6k+6 = \(6\left(k+1\right)⋮6\)
We have 2 cases:
\(\left[{}\begin{matrix}k=2h+1\\k=2k\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}6\left(k+1\right)=6\cdot\left(2h+2\right)=12h+12⋮12\\6\left(k+1\right)=6\left(2h+1\right)=12h+6\equiv6\left(mod12\right)\end{matrix}\right.\)So p+q divided by 12 remainder 0 or 6