Math, asked by ankitprabhakar75, 4 months ago

1/√5-√2-√7 simplify by rationalizing denominator

Answers

Answered by sohanrakhrakh
1

12✓36 please mark me brainleast

Answered by Anonymous
2

Answer:

 \frac{1}{ \sqrt{5} -  \sqrt{2}   -  \sqrt{7} }  \\  \frac{1}{ (\sqrt{5} -   \sqrt{2} ) -  \sqrt{7} }   \\  \frac{1}{( \sqrt{5}  -  \sqrt{2} ) -  \sqrt{7} }  \times  \frac{ (\sqrt{5 }   - \sqrt{2} )  +  \sqrt{7} }{( \sqrt{5} -  \sqrt{2}) +  \sqrt{7} } \\ we \:  \: will \:  \: use \:  \: these \:  \: identities \:  \\ </p><p>( x + y)(x - y) =  {x}^{2}  -  {y}^{2} \\ and \\  (x - y {)}^{2}  =  {x}^{2} +  {y}^{2} - 2xy  </p><p>  \\  =  \frac{( \sqrt{5  }  -  \sqrt{2}) +  \sqrt{7}  }{( \sqrt{5} -  \sqrt{2} {)}^{2} - ( \sqrt{7}  {)}^{2}    }  \\  =   \frac{ \sqrt{5} -  \sqrt{2}  +  \sqrt{7}  }{(( \sqrt{5} {)}^{2}  + ( \sqrt{2 } {)}^{2} - 2 \times  \sqrt{5} \times  \sqrt{2}) - 7 }  \\  \frac{ \sqrt{5 } -  \sqrt{2} +  \sqrt{7}   }{(5 + 2 - 2 \sqrt{10} ) - 7}  \\  =  \frac{ \sqrt{5} -  \sqrt{2}   +  \sqrt{7}  }{7 - 2 \sqrt{10} - 7 }  \\  =  \frac{ \sqrt{5}  -  \sqrt{2}  +  \sqrt{7} }{ - 2 \sqrt{10} }  \\  =   \frac{ \sqrt{5}  -  \sqrt{2} +  \sqrt{7}   }{ - 2 \sqrt{10} } \times  \frac{ - 2 \sqrt{10} }{ - 2 \sqrt{10} }   \\  =  \frac{ - 2 \sqrt{10}( \sqrt{5}  -  \sqrt{2} +  \sqrt{7} )  }{( - 2 \sqrt{10} {)}^{2}  }  \\  =  \frac{ - 2 \sqrt{50 }  + 2 \sqrt{20}  - 2 \sqrt{70} }{40}  \\ hence \:  \: now \:  \: denominator \:  \: is \:  \: rationalized \:

I hope it will help you

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