Answer:
[tex]\dfrac{-x}{3}[/tex]should be added to the given equation.
Step-by-step explanation:
Let a is added to the given equation.
According to the given condition,
[tex]\dfrac{5x}{6}-4+a=\dfrac{x}{2}-4\\\\a=\dfrac{x}{2}-4+4-\dfrac{5x}{6}\\\\a=\dfrac{x}{2}-\dfrac{5x}{6}\\\\a=\dfrac{3x-5x}{6}\\\\a=\dfrac{-2x}{6}\\\\a=\dfrac{-x}{3}[/tex]
So, [tex]\dfrac{-x}{3}[/tex]should be added to the given equation.