1. **State the problem.** Simplify the expression $9x^2 - 5y + 2 + x - 7$. 2. **Use the rule for combining like terms.** Like terms must have the same variable part and the same exponent. - $9x^2$ is a quadratic term. - $x$ is a linear term. - $-5y$ is a $y$-term. - $2$ and $-7$ are constants. 3. **Combine the constant terms.** $$2 - 7 = -5$$ So the expression becomes $$9x^2 + x - 5y - 5$$ 4. **Check for any more like terms.** There are no other terms with the same variable and exponent, so nothing else can be combined. 5. **Final answer.** $$9x^2 + x - 5y - 5$$