Answer:
There is only one solution: x=10
The solution x=4 is an extraneous solution.
Explanation:
We have this equation:

Let's solve for x:
Add x to both sides:

Subtract 6 from both sides:

Raise both sides to the power of two:

Expand out the terms of the right side:

Subtract 2x from both sides and add 4 to both sides:

Factor into a product:

So the solutions are:

Evaluating
:

This solution is correct.
Evaluating
:

So this solution is incorrect.
Therefore:
There is only one solution: x=10
The solution x=4 is an extraneous solution.