Practicing Success

Target Exam

CUET

Subject

General Test

Chapter

Quantitative Reasoning

Topic

Algebra

Question:

If x3 - 4x2 + 19 = 6(x-1) find \(\left[ {x}^{2} + \frac{1}{x-4}\right]\)

Options:

2

4

6

8

Correct Answer:

6

Explanation:

x3 - 4x2 + 19 = 6(x-1)

x2 (x -4) + 19 = 6(x-1)

Divide by (x-4)

⇒ x2 + \(\frac{19}{x-4}\) = \(\frac{6(x-1)}{x-4}\)

⇒ x2 + \(\frac{1}{x-4}\) + \(\frac{18}{x-4}\) = \(\frac{6(x-1)}{x-4}\)

⇒ x2 + \(\frac{1}{x-4}\) = \(\frac{6(x-1)}{x-4}\) - \(\frac{18}{x-4}\)

⇒ \(\left(x^2 + \frac{1}{x-4}\right)\) = \(\frac{6x-6-18}{x-4}\) = \(\frac{6(x-4)}{(x-4)}\)

⇒ \(\left(x^2 + \frac{1}{x-4}\right)\) = 6