Question:
Find the value
$8 a^{3}+27 b^{3}+36 a^{2} b+54 a b^{2}$
Solution:
$=(2 a)^{3}+(3 b)^{3}+3 \times(2 a)^{2} \times 3 b+3 \times 2 a \times(3 b)^{2}$
$=(2 a+3 b)^{3}$
$\left[\therefore a^{3}+b^{3}+3 a^{2} b+3 a b^{2}=(a+b)^{3}\right]$
$=(2 a+3 b)(2 a+3 b)(2 a+3 b)$
$\therefore 8 a^{3}+27 b^{3}+36 a^{2} b+54 a b^{2}$
$=(2 a+3 b)(2 a+3 b)(2 a+3 b)$