Answer
(g-3)(g-15)
Work Step by Step
You are given $g^{2}$-18g+45. Factor it out:
$g^{2}$-15g-3g+45 -break out the b value-
($g^{2}$-15g)+(-3g+45) -group the first two and last two terms-
g(g-15)-3(g-15) -Find the GCF of each grouping-
(g-3)(g-15) -factor out the common term-
=(g-3)(g-15)
