Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If $x-\frac{2}{x}=15$, then what is the value of $\left(x^2+\frac{4}{x^2}\right) ?$

Options:

229

227

221

223

Correct Answer:

229

Explanation:

If $K-\frac{1}{K}=n$

then, $K^2-\frac{1}{K^2}$ = n2 + 2

If $x-\frac{2}{x}=15$

Then,

$\left(x^2+\frac{4}{x^2}\right) ?$ = 152 + 2 × 2 = 229