Question

factorise 2y-7 2y+7 using suitable identity ​

Answer 1

$\huge\colorbox{orange}{Answer}$

$(2y - 7)(2y + 7)$

$it \: is \: in \: the \: form \: of \: \\ (a + b)(a - b) = {a}^{2} - {b}^{2}$

$a = 2y \\ b = 7$

$({2y)}^{2} - {(7)}^{2} \\ 4 {y}^{2} - 49$

Answer 2

$(2y - 7)(2y + 7) \\ we \: know \: that \\ (a - b)(a + b) = a {}^{2} - b {}^{2} \\ here \\ a = 2y \: and \: b = 7 \\ therefore \\ (2y) {}^{2} - (7) {}^{2} \\ 4y {}^{2} - 49$

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