Answer
(x-4y)(x-12y)
Work Step by Step
You are given $x^{2}$-16xy+48$y^{2}$. Factor it out:
$x^{2}$-4xy-12xy+48$y^{2}$ -break out the middle value-
($x^{2}$-4xy)+(-12xy+48$y^{2}$) -group the first two and last two terms-
x(x-4y)-12y(x-4y) -Find the GCF of each grouping-
(x-4y)(x-12y) -factor out the common term-
=(x-4y)(x-12y)
