Find the identity element in the set of all rational numbers except -1 with respect to * defined by `a*b=a+b+a b` .

Explanation

Let `e` be the identity element.

Then according to the definition of the identity element we get,
`a∗e=e∗a=a` for all `a in Q−{−1}`.

Then we have,
`a+e+ae=a`
or, `e(a+1)=0`

Since `a
!=
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