Answer:
x=-8
Step-by-step explanation:

on squaring both sides

either x-2=0 or x+8=0
either x=2 or x=-8
Putting x=2 in original equation, we get

7=7 hence, it is not an extraneous solution
Putting x=-8 in original equation

i.e. 3=-3
Hence, x=-8 is an extraneous solution (since it doesn't satisfy the original equation)
Answer:
No it cannot be concluded.
Step-by-step explanation:
The probability of getting the disease in the first attempt is 50%
The probability of getting the disease in the second attempt is 50%
Thus the probability of getting the disease in either of the turns is 50%+50%=100% (which may seem to be true)
BUT
The probability of not getting the disease in the first attempt is 50%
The probability of not getting the disease in the second attempt is 50%
Thus the probability of not getting the disease in either of the turns is 50%+50%=100% (which is also true for this case)
Thus the probability of getting the disease in either of the 2 contacts is still 50%
Subtract 19 from both sides
-3x=2+x
Subtract x from both sides
-4x=2
Divide both sides by -4
x=-1/2
Final answer: x=-1/2