#### Answer

$(2h+5)(3h-2)(3h+2)$

#### Work Step by Step

$18h^{3}=2.3.3.h.h.h$ and $45h^{2}=3.3.5.h.h$
Hence, $GCF=$$3.3.h.h=9h^{2}$
$8h=2.2.2.h$ and $20=2.2.5$
Hence, $GCF=$$2.2=4$
After grouping:
$=9h^{2}(2h+5)-4(2h+5)$
$=(9h^{2}-4)(2h+5)$
$=(2h+5)(3h-2)(3h+2)$
(since $(a^{2}-b^{2})=(a+b)(a-b)$)