Let L be the language over the alphabet {0, 1, 2, 3, (,), +, -, *, /}, L is the set of operations with correctly formatted natural numbers (a single number is considered to belong to L, 2 – – 3 is an incorrect expression, 2 + 3 is correct, 2 + (-3) is correct. Is it possible to write a regular expression for this language? If not, why?

I think that it is not possible to write a regular expression for this language, because of the operator / we not write 2 / 0 for exemple and are more than a finite number combinations to make this possible. It is correct so?