d) $x^{3}$+9$x^{2}$ +27$x$+27 = $x^{3}$+3.$x^{2}$.3+3.$x$.$3^{2}$+$3^{3}$ = $(x+3)^{3}$
e) 3$\sqrt{3}$$x$-18$x^{2}$+12$\sqrt{3}$$x$-8 = $(\sqrt{3}x)^{3}$-3.$(\sqrt{3}x)^{2}$.2+3.$\sqrt{3}x$-$2^{3}$ = $(\sqrt{3}x-2)^{2}$
f) 27$x^{3}$-27$x$+9$x$-1 = $(3x)^{3}$-3.$3x^{2}$.1+3.3$x$.1-$1^{3}$ = $(3x-1)^{2}$