X^4+11x+10x+11

To simplify the expression \( x^4 + 11x + 10x + 11x^4 + 11x + 10x + 11 \), we can start by combining like terms.

1. First, let's identify the terms:

- \( x^4 \) and \( 11x^4 \) are the \( x^4 \) terms.
- \( 11x, 10x, 11x \), and \( 10x \) are the \( x \) terms.
- Finally, we have the constant term \( 11 \).

2. Now, let's combine the \( x^4 \) terms:
\[
x^4 + 11x^4 = 12x^4
\]

3. Next, combine the \( x \) terms:
\[
11x + 10x + 11x + 10x = 42x
\]

4. The constant term remains \( 11 \).

Putting it all together, we have:
\[
12x^4 + 42x + 11
\]

So, the simplified expression is:
\[
\boxed{12x^4 + 42x + 11}
\]