Question

prove that 2 root 3 +5 is an it rational no. also check whether (2root 3+root 5 )(2root 3 -root 5) is rational or it rational

Answer 1

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Answer 2

$( \sqrt{3 } + 5)( \sqrt{3} - 5) \\ = (\sqrt{3}) {}^{2} - 5 {?}^{2} \\ = 3 - 25 \\ = - 24$
:.it is a rational