Answer:
x=7 satisfy the equation, so it is the solution.
x=4 doesn't satisfy the equation so it is extraneous solution.
Explanation:
The equation given is:

Adding -5 on both sides

Taking square on both sides

Now solving

Verifying solutions:
Putting x=4 in the equation





So, x=4 doesn't satisfy the equation so it is extraneous solution.
Now Putting x=7 and verifying





x=7 satisfy the equation, so it is the solution.