Show that `-a`is not the inverse of `a in N`for the addition operation + on N and `1/a` is not the inverse of `a in N`for multiplication operation `xx`on N, for `a!=1`.

Explanation

To show that \(-a\) is not the inverse of \(a\) in \(\mathbb{N}\) for the addition operation \(+\) on \(\mathbb{N}\) and that \(\frac{1}{a}\) is not the inverse of \(a\) in \(\mathbb{N}\) for the multiplication operation \(\times\) on \(\mathbb{N}\) (for \(a \neq 1\)), we can follow these steps:

### Step 1: Understanding the Inverse for Addition
The additive inverse of a number \(a\) is a number \(b\) such that:
\[ a + b = 0 \]
For \(a\) to have an inverse in \(\mathbb{N}\), both \(a\) and \(b\) must belong to \(\mathbb{N}\).
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