All Exams Test series for 1 year @ ₹349 only
Question

If \(\dfrac{x}{x+1}+\dfrac{x+1}{x} = \dfrac52\), then find x.

This question was previously asked in
RRB NTPC 2025 Under Graduate CBT 1 Question Paper PDF (20-Jun-2026) (Shift 3)
The correct answer is

1 or -2

Let \(u = \dfrac{x}{x+1}\), so the equation becomes \(u+\dfrac1u = \dfrac52\).

\(2u^2-5u+2=0 \Rightarrow u = 2\ \text{or}\ u=\dfrac12\).

If \(u=2\): \(\dfrac{x}{x+1}=2 \Rightarrow x=2x+2 \Rightarrow x=-2\).

If \(u=\tfrac12\): \(\dfrac{x}{x+1}=\tfrac12 \Rightarrow 2x=x+1 \Rightarrow x=1\).

Hence, the values of x are 1 or -2.

Was this answer helpful?

Similar Questions

  1. Simplify: $3((\frac{5}{3})x^2 - 28x + 15) - 5(x^2 + 6x - 15)$

  2. The product of two positive numbers is 1445. If the first number is five times of the second number, then the sum of the two numbers is:
  3. The value of $x$ satisfying the equation $x^2 + a^2 = (b - x)^2$ is:
  4. Out of four consecutive numbers, the sum of the first two numbers is equal to the fourth number. What is half of the sum of the four numbers?
  5. If $p = 5 - 2\sqrt{6}$, then find the value of $p^2 + \frac{1}{p^2}$
  6. Which of the following number, when added to itself 14 times gives 135 as result?
  7. Simplify $x(7x - 2) + 5(x^2 - 3) + 13$.
  8. What is the number of all positive solutions of the equation $|x \times 1| = 0$ ?
  9. If $a + b = 5$ and $ab = 13$, then what will be the value of $a^3 + b^3$?
  10. The value of $p^2 - 7p + 12$ at $p = 3$ is:

Important Questions from Algebric Equations

  1. If m + n = 24, then (m - 16)³ + (n - 8)³ is ____.

  2. For the following equations, what are the values of a and b to have infinitely many solutions?

    ax + by = 2

    3x - (5 - 2ay) = 6

  3. If m + n = 24, then (m - 16)³ + (n - 8)³ is ____.

  4. For the following equations, what are the values of a and b to have infinitely many solutions?

    ax + by = 2

    3x - (5 - 2ay) = 6

  5. Simplify the following expression: 
    \(\frac{(x - y)^3 + (y - z)^3 + (z - x)^3}{(x - y)(y - z)(z - x)}\)

Need Expert Advice?
Upcoming Exams
RRB ALP
July 28, 2026
RRB Group D
August 03, 2026
Test Series
RRB NTPC img
Railways
RRB NTPC Under Graduate 2026 New Mock Test Series
1459 Tests 2 Tests Free
215 Attempts
4.3(512)
English, Hindi, Telugu +7 More

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App