Answer:
See below ~
Explanation:
Analyzing Question 2 :
⇒
⇒
(Correct)
⇒
(Correct)
⇒
(Incorrect ×)
This step is incorrect because on multiplying the denominator it should be √4, equal to 2.
The correct step will be :
⇒
(Correct) (Final solution)
Analyzing Question 3 :
⇒
⇒
(Step is theoretically correct, but solution won't be possible here)
⇒
(Incorrect ×)
This step is incorrect because the square root of x² - 4 cannot be taken. (x - 2) would be the value of the root of (x - 2)² = x² - 4x + 4.
Resolving by alternative method :
⇒
(Correct)
⇒
(Correct)
⇒ x = ±2 (Correct) (Final solution)