(x²+x+1)+(x²-x+1)

To simplify the given expression, we can combine like terms:

(x² + x + 1) + (x² - x + 1) = x² + x + 1 + x² - x + 1

Combining the x² terms: x² + x² = 2x² Combining the x terms: x - x = 0 Combining the constant terms: 1 + 1 = 2

Therefore, the simplified expression is:

2x² + 2