Question
Write the lowest rationalising factor of $: 7 - \sqrt7$
✓
Answer
$7 - \sqrt7$
$( 7 - \sqrt7 )( 7 + \sqrt7 )$
$= 49 - 7$
$= 42$
Therefore, lowestrationalizing factor is $( 7 + \sqrt7 ).$
$( 7 - \sqrt7 )( 7 + \sqrt7 )$
$= 49 - 7$
$= 42$
Therefore, lowestrationalizing factor is $( 7 + \sqrt7 ).$
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