1. The problem is to combine the terms $-288x$ and $-288x$. 2. When combining like terms, you add or subtract their coefficients while keeping the variable part the same. 3. The terms are both $-288x$, so we add the coefficients: $$-288 + (-288) = -288 - 288$$ 4. Calculate the sum: $$-288 - 288 = -576$$ 5. Attach the variable $x$ back to the combined coefficient: $$-576x$$ 6. Therefore, the combined expression is $-576x$.