Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If (x − 5) = −1, then the value of $x^ 3(x^ 3 − 110)$ =?

Options:

0

-1

1

2

Correct Answer:

-1

Explanation:

If x + \(\frac{1}{x}\)  = n

then, $x^3 +\frac{1}{x^3}$ = n3 - 3 × n

If x(x − 5) = −1

Then, x - 5 = \(\frac{-1}{x}\)

x + \(\frac{1}{x}\) = 5

$x^3 +\frac{1}{x^3}$ = 53 - 3 × 5 = 110

$x^ 3(x^ 3 − 110)$ = -1