Example of an Element in the Product of Ideals that Cannot be Written as the Product of Two Elements
Problem 623
Let $I=(x, 2)$ and $J=(x, 3)$ be ideal in the ring $\Z[x]$.
(a) Prove that $IJ=(x, 6)$.
(b) Prove that the element $x\in IJ$ cannot be written as $x=f(x)g(x)$, where $f(x)\in I$ and $g(x)\in J$.
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