Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If a - \(\frac{1}{a - 5}\) = 27

Then find , (a - 5)3 - \(\frac{1}{(a - 5)^3}\)

Options:

10663

17896

12675

13564

Correct Answer:

10663

Explanation:

Given = a - \(\frac{1}{a - 5}\) = 27

By subtracting 5 on both sides we get,

(a - 5) - \(\frac{1}{a - 5}\) = 27 - 5 = 22

(a - 5)3 - \(\frac{1}{(a - 5)^3}\) = 223 + 3 × 5 = 10663

 

Note - if x -  \(\frac{1}{x}\) = a

then x3 - \(\frac{1}{x^3}\) =  a3 + 3a