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Example 20 - Chapter 1 Class 9 Number Systems (Term 1)
Last updated at Jan. 31, 2022 by Teachoo
Examples
Example 1 (i)
Example 1 (ii)
Example 1 (iii) Important
Example 2
Example 3
Example 4 Important
Example 5
Example 6
Example 7 Important Deleted for CBSE Board 2023 Exams
Example 8
Example 9 Important Deleted for CBSE Board 2023 Exams
Example 10 Important Deleted for CBSE Board 2023 Exams
Example 11
Example 12 Important
Example 13
Example 14
Example 15 Important
Example 16 (i) Important Deleted for CBSE Board 2023 Exams
Example 16 (ii)
Example 16 (iii)
Example 16 (iv)
Example 17
Example 18
Example 19 Deleted for CBSE Board 2023 Exams
Example 20 Important You are here
Example 21 (i) Deleted for CBSE Board 2023 Exams
Example 21 (ii)
Example 21 (iii) Important
Example 21 (iv) Important
Transcript
Example 20 Rationalize the denominator of 1/(7 + 3√2 ). 1/(7 + 3√2 ) = 1/(7 + 3√2) × (𝟕 − 𝟑√𝟐)/(𝟕 − 𝟑√𝟐) = (7 − 3√2)/(7 + 3√2)(7 − 3√2) = (7 − 3√2)/((𝟕)^𝟐 − (𝟑√𝟐)^𝟐 ) = (7 − 3√2)/(49 − (3 × 3 × √2 × √2) ) = (7 − 3√2)/(49 − (9 × 2) ) ( As (a + b)(a – b) = a2 – b2 ) = (7 − 3√2)/(49 − 18) = (𝟕 − 𝟑√𝟐)/𝟑𝟏
