Can You Simplify This?

Algebra Level 2

2 + 6 2 + 3 = ? \Large \frac{\sqrt2 + \sqrt6}{ \sqrt{2+\sqrt3}} =?


The answer is 2.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

4 solutions

Richard Grayson
Jun 29, 2015

If we square the expression, we get 2 + 2 2 6 + 6 2 + 3 = 8 + 4 3 2 + 3 = 4 , \frac{2 + 2\sqrt{2\cdot 6} + 6}{2+\sqrt{3}} = \frac{8+4\sqrt{3}}{2+\sqrt{3}} = 4, So, since the expression is positive, it must equal 4 = 2. \sqrt{4}=2.

the answer comes to 4, then why are we finding its square root??

Samriddhi Singha Roy - 5 years, 8 months ago

Log in to reply

@Samriddhi Singha Roy The square of the expression comes out to be 4 4 ,so in order to find the value of the original expression,we have to find its square root.

Abdur Rehman Zahid - 5 years, 7 months ago

this is wrong or maybe i didnt get it, but when i used a calculator i get 2.19275263435

Ashwath Srikanthan - 5 years, 8 months ago

Log in to reply

you must have done some thing wrong. my calculator gives me 2

Yasir Soltani - 5 years, 8 months ago

XD I'm in yr 9 and not good at simplifying so it was pretty much a half guess for me and my working out was as simple as... Since you can change \sqrt{2} + \sqrt{6} into \sqrt{2 + 6} You can change \sqrt{2 + \sqrt{3}} into \sqrt{2} + \sqrt{3}

making it possible to write it as: \frac {\sqrt{2} + \sqrt{6}} {\sqrt{2} + \sqrt{3}}

And so the \sqrt {2} cancel out and \frac {\sqrt {6}} {/sqrt {3}} = 2

P.S I'm new to this website and in the preview the symbols aren't working and I don't know why so hope you can understand if this fails :P

Katsura Guregorī - 5 years, 8 months ago

Log in to reply

you can't write it that way!

Yasir Soltani - 5 years, 8 months ago

Log in to reply

I kinda figured but meh

Katsura Guregorī - 5 years, 8 months ago
Yasir Soltani
Nov 9, 2015

Let 2 + 6 2 + 3 = x \large \frac{\sqrt2 + \sqrt6}{\sqrt{2 + \sqrt3}} = x squaring both sides 2 + 2 × 2 × 6 + 6 2 + 3 = x 2 \large \frac{2 +2\times \sqrt{2}\times \sqrt{6} +6}{2 + \sqrt{3}} = x^2 4 ( 2 + 3 ) 2 + 3 = x 2 \large \frac{ 4(2 + \sqrt{3})}{2 + \sqrt{3}} = x^2 x 2 = 4 \large x^2 = 4 x = 2 \large x =2 since x is positive

There's a typo.

x = 2 x=2

Kenneth Choo - 5 years ago

Log in to reply

edited, thank you

Yasir Soltani - 5 years ago
Owen Leong
Oct 3, 2015

sqrt( 2 ) + sqrt( 6 ) = sqrt( 8 + 2 sqrt( 12 ) ) = sqrt( 8 + 4 sqrt( 3 ) ) = 2 sqrt( 2 + sqrt( 3 ) )

Hence ( sqrt( 2 ) + sqrt( 6 ) ) / sqrt( 2 + sqrt( 3 ) ) = 2

Emilio Garcia
Oct 8, 2015

most simple?

You cant cross out things that aren't being multiplied

Pridhvi Myneni - 5 years, 8 months ago

Log in to reply

that's....nice son

Bloons Qoth - 5 years ago

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...