1. **State the problem:** We need to simplify the expression by adding the terms involving $x^2$, specifically $8x^2 + (-5x^2)$. 2. **Recall the rule for adding like terms:** When adding terms with the same variable and exponent, add their coefficients and keep the variable part unchanged. 3. **Apply the rule:** $$8x^2 + (-5x^2) = (8 + (-5))x^2 = 3x^2$$ 4. **Interpretation:** Adding $8x^2$ and $-5x^2$ results in $3x^2$. This means the combined coefficient for $x^2$ is 3. 5. **Summary:** To add $8x^2$ and $-5x^2$, simply add their coefficients $8 + (-5) = 3$, so the result is $3x^2$.