Simplify. \( -\frac{3 x}{4-x}-\frac{x+4}{x-4} \)

Calculate or simplify the expression \( -\frac{3x}{4-x}-\frac{x+4}{x-4} \). Simplify the expression by following steps: - step0: Solution: \(-\frac{3x}{4-x}-\frac{x+4}{x-4}\) - step1: Reduce fractions to a common denominator: \(-\frac{3x}{4-x}-\frac{\left(x+4\right)\left(-1\right)}{\left(x-4\right)\left(-1\right)}\) - step2: Reorder the terms: \(-\frac{3x}{4-x}-\frac{\left(x+4\right)\left(-1\right)}{-\left(x-4\right)}\) - step3: Rewrite the expression: \(-\frac{3x}{4-x}-\frac{\left(x+4\right)\left(-1\right)}{4-x}\) - step4: Transform the expression: \(\frac{-3x-\left(x+4\right)\left(-1\right)}{4-x}\) - step5: Multiply the terms: \(\frac{-3x-\left(-x-4\right)}{4-x}\) - step6: Subtract the terms: \(\frac{-2x+4}{4-x}\) The simplified expression is \( \frac{-2x+4}{4-x} \).