Prove that x=`underset(91 "times")ubrace(1111,....)` is composite number.

Explanation

To prove that \( x = 111 \ldots 1 \) (91 times) is a composite number, we can follow these steps:

### Step 1: Express \( x \) in a mathematical form
We can express \( x \) as:
\[ x = 111 \ldots 1 \quad (\text{91 times}) \]
This can be rewritten as:
...