16Hit1600
Advanced MathVery hardSimplifying a fraction with a negative exponent

Advanced Math practice question

For x > 0 and x ≠ 1, which expression is equivalent to (x⁻¹ − 1)/(1 − x)?

  1. A. 1/xCorrect
  2. B. −1/x
  3. C. x
  4. D. −1

Answer: A. 1/x

x⁻¹ − 1 = (1 − x)/x, and dividing by (1 − x) leaves 1/x.

Why the other answers are wrong

B. −1/x
The signs of numerator and denominator match, so the result is positive.
C. x
This inverts the correct answer.
D. −1
This forgets the factor of x in the denominator.

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