Question
Factorise the following using the identity $a^2-b^2=(a+b)(a-b)$.
$\frac{\text{x}^3\text{y}}{9}-\frac{\text{xy}^3}{16}$

Answer

$\frac{\text{x}^3\text{y}}{9}-\frac{\text{xy}^3}{16}$$=\text{xy}\Big(\frac{\text{x}^2}{9}-\frac{\text{y}^2}{16}\Big)$
$=\text{xy}\bigg[\Big(\frac{\text{x}}{3}\Big)^2-\Big(\frac{\text{y}}{4}\Big)^2\bigg]$
$=\text{xy}\Big(\frac{\text{x}}{3}+\frac{\text{y}}{4}\Big)\Big(\frac{\text{x}}{3}-\frac{\text{y}}{4}\Big)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free