Question

[5+2√3] [5 -2√3] = ?
​a) 15 b) 21 c) 12 d) 13

Answer 1

AnswEr :

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$:\implies\sf{(5+2\sqrt{3})(5-2\sqrt{3})}$

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$:\implies\sf{(5)^2-(2\sqrt{3})^2}$

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$:\implies\sf{25-(4\times 3)}$

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$:\implies\sf{25-12}$

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$:\implies\sf{13}$

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Identity Used :

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• a² - b² = (a + b) (a - b)

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