Answer
$2b\sqrt {b}$
Work Step by Step
$\sqrt {9b^3}-\sqrt {25b^3}+\sqrt {16b^3}$ Factor.
$\sqrt {9b^2}\sqrt {b}-\sqrt {25b^2}\sqrt {b}+\sqrt {16b^2}\sqrt {b}$ Simplify.
$3b\sqrt {b}-5b\sqrt {b}+4b\sqrt {b}$ Combine like radicals.
$2b\sqrt {b}$
