To simplify the expression $(-9x^2 + 4x - 4) + (3x^2 + 5x)$, follow these steps:

Step 1: Combine like terms

• Combine $x^2$ terms: $-9x^2 + 3x^2 = -6x^2$
• Combine $x$ terms: $4x + 5x = 9x$
• Combine constants: $-4$ (only one constant term here)

Step 2: Write the simplified expression

The simplified form is:

$-6x^2 + 9x - 4$

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Related Questions:

1. How do you add and subtract polynomials step by step?
2. How do you simplify expressions with multiple variables?
3. What are like terms, and why are they important in algebra?
4. How do you factor polynomials like $-6x^2 + 9x - 4$?
5. What are common mistakes to avoid when combining like terms?

Tip:

Always align terms by degree (powers of $x$) when adding or subtracting polynomials to make the process easier.