Question

${x }^{2} - 3 {x}^{2} - 9x - 5$

Answer 1

☆Hey friend!!! ☆

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Here is your answer ☞
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$(a) \: = > {x}^{2} + 7x + 10 \\ \\ = > {x}^{2} + 5x + 2x + 10 \\ \\ = > {x}^{2} + 2x + 5x + 10 \\ \\ = > x(x + 2) + 5(x + 2) \\ \\ = > (x + 5)(x + 2) \\ \\ then \\ \\ = > x = - 5 \: \: \: \: or \: \: \: \: x = - 2 \\ \\ hence \: the \: zeros \: of \: polynomial \: is \: - 5 \: and \: - 2 \\ \\ \\ \\ (b) = > {x}^{2} - 25 \\ \\ we \: know \: that \: \\ ( {a}^{2} - {b}^{2} ) = (a + b)(a - b) \\ \\ by \: using \: this \: property \\ \\ = >( \ {x }^{2} - 25) = ( {x}^{2} - {5}^{2} ) \\ \\ = > (x + 5)(x - 5) \\ \\ = > x = - 5 \: \: \: \: \: or \: \: \: \: x = 5 \\ \\ hence \: the \: \: zeros \: are \: 5 \: and \: - 5$

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Devil_king ▄︻̷̿┻̿═━一