Question
Factorise the following using the identity $a^2- b^2= (a + b)(a - b).$
$\text{x}^2-\frac{\text{y}^2}{100}$

Answer

$\text{x}^2-\frac{\text{y}^2}{100}$$=\text{x}^2-\Big(\frac{\text{y}}{10}\Big)^2$
$=\Big(\text{x}+\frac{\text{y}}{10}\Big)\Big(\text{x}-\frac{\text{y}}{10}\Big)$

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