16Hit1600
Advanced MathHardDifference of two squared radical binomials

Advanced Math practice question

For x > 0, which expression is equivalent to (√x + 1)² − (√x − 1)²?

  1. A. 4√xCorrect
  2. B. 2
  3. C. 4x
  4. D. 2√x

Answer: A. 4√x

(x + 2√x + 1) − (x − 2√x + 1) = 4√x.

Why the other answers are wrong

B. 2
The constants cancel; the middle terms do not.
C. 4x
The x terms cancel.
D. 2√x
The middle terms add to 4√x, not 2√x.

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