Rationalising

Laws of exponents →
Chapter 1 Class 9 Number Systems
Concept wise

Example 19 - Chapter 1 Class 9 Number Systems

Last updated at August 13, 2026 by

Example 19 - Rationalise the denominator of 1/(7+3 root 2) - Examples

part 2 - Example 19 - Examples - Serial order wise - Chapter 1 Class 9 Number Systems

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Transcript

Example 19 Rationalize the denominator of 1/(7 + 3โˆš2 ). 1/(7 + 3โˆš2 ) = 1/(7 + 3โˆš2) ร— (๐Ÿ• โˆ’ ๐Ÿ‘โˆš๐Ÿ)/(๐Ÿ• โˆ’ ๐Ÿ‘โˆš๐Ÿ) = (7 โˆ’ 3โˆš2)/(7 + 3โˆš2)(7 โˆ’ 3โˆš2) = (7 โˆ’ 3โˆš2)/((๐Ÿ•)^๐Ÿ โˆ’ (๐Ÿ‘โˆš๐Ÿ)^๐Ÿ ) = (7 โˆ’ 3โˆš2)/(49 โˆ’ (3 ร— 3 ร— โˆš2 ร— โˆš2) ) = (7 โˆ’ 3โˆš2)/(49 โˆ’ (9 ร— 2) ) ( As (a + b)(a โ€“ b) = a2 โ€“ b2 ) = (7 โˆ’ 3โˆš2)/(49 โˆ’ 18) = (๐Ÿ• โˆ’ ๐Ÿ‘โˆš๐Ÿ)/๐Ÿ‘๐Ÿ

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