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Find the value of a and b : √11– √7/√11 + √7 = a–b √77 |
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Answer» ANSWERRationalize the LEFT hand side,11 + 7 11 − 7 = 11 + 7 11 − 7 × 11 − 7 11 − 7 = ( 11 + 7 )( 11 − 7 )( 11 − 7 ) 2 = ( 11 ) 2 −( 7 ) 2 ( 11 ) 2 +( 7 ) 2 −2( 11 )( 7 ) = 11−711+7−2 77 = 418−2 77 = 418 − 42 77 = 29 − 21 77 Now,29 − 21 77 =a−B 77 ⇒a= 29 ,b= 21 a+b= 29 + 21 = 210 =5 |
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