The expression $x + 1 + x$ can be simplified as follows:

$x + x + 1 = 2x + 1$

So, the simplified form of the expression is $2x + 1$.

Would you like a more detailed explanation or have any questions about this?

Here are some related questions for further practice:

1. How do you simplify expressions with multiple variables like $3x + 4y + 2x$?
2. What happens when you substitute $x = 2$ into the simplified expression $2x + 1$?
3. How do you solve for $x$ in an equation like $2x + 1 = 7$?
4. Can you simplify the expression $4x + 2 + 3x - 1$?
5. How do you factor the expression $2x + 2$?

Tip: When simplifying expressions, always look for like terms—terms that have the same variable raised to the same power—and combine them.