ANSWER
18. No extraneous solution.
19. The extraneous solution is x=-2
Step-by-step explanation
18. The given radical equation is:

Solving this radical equation yields

We check for an extraneous solution by substituting each value into the equation.
Checking for x=1,




This is true.
Checking for x=2




This is also true. Hence there is no extraneous solution.
19. The given radical equation is:

Solving this equation yields,

Checking for x=3,.


3=3.
This is a true solution.
Checking for x=-2.



Hence x=-2 is an extraneous solution.