Question

factorise 3rd sum from the following

Answer 1

Here's your answer mate

Using identity
$( {x}^{3} - {y}^{3} ) = {x}^{3} - {y}^{3} - 3 {x}^{2} y + 3x {y}^{2}$
so

Answer is as follows::

$( {1}^{3} ) - ( {4}^{3} ) - 3 \times ( {1}^{2} ) \times 4 + 3 \times 1 \times {4}^{2}$

$= (1 + 4)^{3}$

Hope it Helps buddy!!