Answer:
The Solution is (-6).
Explanation:
Given:

We need to solve the equation.
Solution:

Now applying distributive property we get;

Applying the given rule we get;

Now we know that;
When (+) is met with the (-) the result is (-).
So we get;

Now adding both side by 16 using addition property of equality we get;

Now we will divide both side by -8 using division property of equality we get;

Hence The Solution is (-6).