1. The problem appears to be about simplifying or evaluating an expression involving $x$ and plus/minus signs, but the exact expression is unclear from the input. 2. Since the input is ambiguous, I will interpret it as simplifying the expression $x + x + (-x) + (-x)$. 3. The formula for combining like terms is to add or subtract their coefficients: $a x + b x = (a+b)x$. 4. Applying this rule, we have: $$x + x + (-x) + (-x) = (1 + 1 - 1 - 1)x$$ 5. Simplify the coefficients: $$1 + 1 - 1 - 1 = \cancel{1 + 1} - \cancel{1 + 1} = 0$$ 6. Therefore, the entire expression simplifies to: $$0 \times x = 0$$ 7. So, the final answer is $0$. This means all terms cancel each other out, resulting in zero.