Answer:
1)a)
b)
2) Solving and Checking on section 1 3) Commonly when we square both sides and there's an x on the right side outside the radical equation, an extraneous solution arises.
Step-by-step explanation:
1 &2) An extraneous solution does not satisfy an equation. So let's evaluate:



Checking for extraneous solution:


1 and 2) Another radical equation:


Checking:

4 satisfies the equation.
3) Because when we change the radical equation into quadratic one, and both sides are squared, very often the second solution does not satisfy the equation. That happened when we squared x.