Evaluate..........

Algebra Level 2

2 6 2 + 3 + 5 ( 2 + 3 5 ) \frac { 2\sqrt { 6 } }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } -(\sqrt { 2 } +\sqrt { 3 } -\sqrt { 5 } )


The answer is 0.

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.

2 solutions

Samarth Sangam
Sep 7, 2014

2 6 2 + 3 + 5 ( 2 + 3 5 1 ) b y t a k i n g L C M o f 2 + 3 + 5 a n d 1 w e g e t 2 + 3 + 5 2 6 ( 2 + 3 5 ) ( 2 + 3 + 5 ) 2 + 3 + 5 s i m p l y f i n g t h i s w e g e t 2 6 [ ( 2 + 3 ) 2 5 ] 2 + 3 + 5 t h e n u m e r a t o r i s 0 t h e r e f o r e a n s w e r i s 0 \frac { 2\sqrt { 6 } }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } -(\frac { \sqrt { 2 } +\sqrt { 3 } -\sqrt { 5 } }{ 1 } )\\ by\quad taking\quad LCM\quad of\quad \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } \quad and\quad 1\quad we\quad get\quad \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } \\ \frac { 2\sqrt { 6 } -(\sqrt { 2 } +\sqrt { 3 } -\sqrt { 5 } )(\sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } ) }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } \\ simplyfing\quad this\quad we\quad get\quad \frac { 2\sqrt { 6 } -[{ (\sqrt { 2 } +\sqrt { 3 } ) }^{ 2 }-5] }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } \\ the\quad numerator\quad is\quad 0\quad therefore\quad answer\quad is\quad 0

Adam Zaim
Sep 18, 2014

2 6 2 + 3 + 5 ( 2 + 3 5 ) L e t a = 2 , b = 3 , c = 5 . 2 6 = 2 × 6 1 2 = 2 × ( 3 × 2 ) 1 2 = 2 × 3 × 2 = 2 a b 2 a b a + b + c ( a + b c ) = 2 a b a + b + c ( a 2 + a b + a c a + b + c + a b + b 2 + b c a + b + c a c + b c + c 2 a + b + c ) = 2 a b a + b + c ( a 2 + b 2 c 2 + 2 a b a + b + c ) = 2 a b 2 a b a 2 b 2 + c 2 a + b + c = 2 3 + 5 2 + 3 + 5 = 0 2 + 3 + 5 = 0 \frac { 2\sqrt { 6 } }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } -(\sqrt { 2 } +\sqrt { 3 } -\sqrt { 5 } )\\ \\ Let\quad a=\sqrt { 2 } ,\quad b=\sqrt { 3 } ,\quad c=\sqrt { 5 } .\\ \\ 2\sqrt { 6 } =2\times { 6 }^{ \frac { 1 }{ 2 } }=2\times { (3\times 2) }^{ \frac { 1 }{ 2 } }=2\times \sqrt { 3 } \times \sqrt { 2 } =2ab\\ \\ \frac { 2ab }{ a+b+c } -(a+b-c)\\ =\frac { 2ab }{ a+b+c } -(\frac { { a }^{ 2 }+ab+ac }{ a+b+c } +\frac { ab+{ b }^{ 2 }+bc }{ a+b+c } -\frac { ac+bc+{ c }^{ 2 } }{ a+b+c } )\\ =\frac { 2ab }{ a+b+c } -(\frac { { a }^{ 2 }+{ b }^{ 2 }-{ c }^{ 2 }+2ab }{ a+b+c } )\\ =\frac { 2ab-2ab-{ a }^{ 2 }-{ b }^{ 2 }+{ c }^{ 2 } }{ a+b+c } \\ =\frac { -2-3+5 }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } \\ =\frac { 0 }{ \sqrt { 2 } +\sqrt { 3 } +\sqrt { 5 } } \\ =0

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...