## Simplifying Polynomial Expressions

This article will demonstrate how to simplify the polynomial expression:
**(3x^2 - x + 1) + (15 - 9x - 2x^2)**

### Understanding the Process

To simplify this expression, we need to combine like terms. **Like terms** are terms that have the same variable and exponent.

**Step 1: Remove the Parentheses**

Since we are adding the two polynomials, the parentheses don't affect the signs of the terms. We can simply remove them:

**3x^2 - x + 1 + 15 - 9x - 2x^2**

**Step 2: Combine Like Terms**

Identify and group the like terms together:

**x^2 terms:**3x^2 - 2x^2**x terms:**-x - 9x**Constant terms:**1 + 15

**Step 3: Simplify**

Now, combine the coefficients of the like terms:

**x^2 terms:**(3 - 2)x^2 =**x^2****x terms:**(-1 - 9)x =**-10x****Constant terms:**1 + 15 =**16**

**Step 4: Final Expression**

Combine all the simplified terms to get the final expression:

**x^2 - 10x + 16**

### Conclusion

Therefore, the simplified form of the polynomial expression **(3x^2 - x + 1) + (15 - 9x - 2x^2)** is **x^2 - 10x + 16**.