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

$(\sqrt{5} + \sqrt{11})(\sqrt{5} - \sqrt{11})$ is equal to:

This question was previously asked in
RRB NTPC 2019 CBT 1 Question Paper PDF (31-Jan-2021) (Shift 1)
The correct answer is
-6

Simplify Radical Expression $(\sqrt{5} + \sqrt{11})(\sqrt{5} - \sqrt{11})$

The given expression is in the form of a difference of squares, which follows the algebraic identity: $(a+b)(a-b) = a^2 - b^2$

In this expression, let $a = \sqrt{5}$ and $b = \sqrt{11}$.

Applying the difference of squares formula:

$(\sqrt{5} + \sqrt{11})(\sqrt{5} - \sqrt{11}) = (\sqrt{5})^2 - (\sqrt{11})^2$

Now, we evaluate the squares:

  • $(\sqrt{5})^2 = 5$
  • $(\sqrt{11})^2 = 11$

Substitute these values back into the equation:

$5 - 11$

Performing the subtraction:

$-6$

Thus, the expression $(\sqrt{5} + \sqrt{11})(\sqrt{5} - \sqrt{11})$ simplifies to $-6$.

Was this answer helpful?

Similar Questions

  1. If $\sqrt{45} + \sqrt{125} = 17.89$, then what will be the value of $\sqrt{180} + \sqrt{80}$?
    (Give your answer to one decimal place.)
  2. What is the value of $\frac{4+\sqrt{2}}{\sqrt{2}+1}$?
  3. If $\sqrt{2916} = 54$ then what is the value of the following? 

    $\sqrt{29.16} + \sqrt{0.2916} + \sqrt{0.002916} + \sqrt{0.00002916}$

  4. What is the value of $\sqrt{75} + \sqrt{147}$?
  5. Find $\sqrt{\frac{1521}{1849}}$
  6. If $\frac{2\sqrt{2}+\sqrt{7}}{2\sqrt{2}-\sqrt{7}} = x + y\sqrt{14}$, find the value of y.

  7. If $x = 7 + 4\sqrt{3}$, then find the value of $\sqrt{x} + \frac{1}{\sqrt{x}}$
  8. If $\frac{3\sqrt{5} - 5}{3\sqrt{5} + 5} = a + b\sqrt{5}$, then find the value of b.
  9. Calculate the value of $\sqrt{80} + 4\sqrt{5}$ if $2\sqrt{5} + \sqrt{125} = 7x$
  10. What is the value of $\frac{\sqrt{5}+1}{\sqrt{5}-1}$ ?

Important Questions from Surds and Indices

  1. The cube root of - 64 × - 1331 is:

  2. If (27) m = (81) n, then m 2: mn = ?

  3. if 49 n +  49 n  +  49 n  +  49 n  +  49 n  +  49 n +  49 n  = 7 2221 , then n = ? 

  4. If a x= b y= c zand b 2= ac then y =

  5. The value of (0.3) [{(200 - 146)/(3 × 3 × 3)} - 3] is:

Need Expert Advice?
Upcoming Exams
RRB ALP
November 03, 2026
Test Series
RRB NTPC img
Railways
RRB NTPC Under Graduate 2026 New Mock Test Series
1612 Tests 1 Tests Free
1020 Attempts
4.3(516)
English, Hindi, Telugu +7 More
More Questions from RRB NTPC

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