Question 4: Factorize:
\((v)\) \(\; \) \(343x^3+216 \)
Solution:
$\displaystyle\ \ \ \ 343x^{3} +216$
$\displaystyle =( 7x)^{3} +6^{3}$
$\displaystyle =( 7x+6)\left[( 7x)^{2} -( 7x)( 6) +6^{2}\right]$
$\displaystyle =( 7x+6)\left( 49x^{2} -42x+36\right)$