To simplify the expression 5x² + 3x + 4 + 2x² + 6x + 3, we start by combining like terms.
1. **Identify like terms**: In this expression, we have:
- Quadratic terms: 5x² and 2x²
- Linear terms: 3x and 6x
- Constant terms: 4 and 3
2. **Combine the quadratic terms**:
5x² + 2x² = 7x²
3. **Combine the linear terms**:
3x + 6x = 9x
4. **Combine the constant terms**:
4 + 3 = 7
Putting it all together, we get:
7x² + 9x + 7
This expression is now simplified and cannot be reduced further. Thus, the final answer is 7x² + 9x + 7.