(x²+x+1)+(x²-x+1)

To simplify the expression (x²+x+1)+(x²-x+1), you can combine the like terms.

The terms with x² are (x² + x²), which simplifies to 2x².

The terms with x are (x + (-x)), which simplifies to 0.

The constant terms are 1 and 1, which add up to 2.

Therefore, the simplified expression is 2x² + 2.