## College Algebra 7th Edition

$6\sqrt{x^2+y^2}$
Factor the radicand so that one of the factors is a perfect square to obtain: $=\sqrt{36(x^2+y^2)} \\=\sqrt{6^2(x^2+y^2)}$ Simplify the radical to obtain: $=6\sqrt{x^2+y^2}$