I have a system of congruence equations
$$ \begin{cases} x \equiv 17 \pmod{15} \\ x \equiv 14 \pmod{33} \end{cases} $$
I need to investigate the system and see if they've got any solutions.
I know that I should use the Chinese remainder theorem "in a reverse order" so I think I should split each congruence equation in two new systems of two congruence equations.
From the CRT two congruence equations can be joined in a single congruence equation by
$$ x \equiv b_1 + c n_1 (b_2 - b_1) \pmod{n_1 n_2} $$
From the first congruence equation I can get these two $$ b_1 + c n_1 (b_2 - b_1) = 17 \\ n_1 n_2 = 15 $$
and from the second I can get $$ b_1 + cn_1 (b_2 - b_1) = 14 \\ n_1 n_2 = 33 $$
but the unknown variables are not combined so I cannot just solve the system of four equations.
I need a hint :-)
$x\equiv2(\mod15)\implies x=15k+2$ for some integer $k$. Similarly $x=33m+14$.
Thus $15k+2=33m+14\implies15k-33m=12\implies5k-11m=4$.
$\gcd(5,11)=1$ so the equation above has solutions.