Question

Factorise the following x^2-3x-28​

Answer 1

$\sf\purple{\underline{\underline{Question}}}$

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$\small\tt{x^{2}\:-\:3x\:-28}$

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$\sf\purple{\underline{\underline{Answer}}}$

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$\small\tt{x^{2}\:-\:3x\:-28}$

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$\small\text{Splitting the middle term so there product }\\{\small\text{will be 28 and sum will be 3}}$

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$\small\text{Taking lcm of 28}$

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$\small\text{Factors we get , 2 , 2 , 7 }$

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$\small\text{Now taking these three factore in such way so}\\{\small\text{while adding we will get the sum of 3}}$

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$\small\tt{Will\:take\: (2\times2 - 7 \:= \:-3}$

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$\small\longrightarrow\tt{x^{2}\:-\:7x\:+4x\:-28}$

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$\small\longrightarrow\text{x (x-7) +4 (x-7)}$

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$\small\longrightarrow\text{(x+4) (x-7)}$

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$\small\longrightarrow\text{(x+4) (x-7) = 0}$

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• $\small\longrightarrow\text{x+4 = 0 = -4}$

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• $\small\longrightarrow\text{x-7 = 0 = 7}$

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$\small\text{We get the value of x are }{\small\sf\red{-4 \:and\: 7}}$

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$\sf\purple{\underline{\underline{Thanks}}}$