Answer
$105c \sqrt 3c$
Work Step by Step
$(3 \sqrt 5c) \times (7 \sqrt 15c^{2}) $
We multiply the constants 7 and 3. We multiply the numbers inside the square root.
$(3)(7) (\sqrt (5c \times 15c^{2}))$
$21 \sqrt 75c^{3}$
$75c^{3}$ has the factors of $25c^{2} \times 3c$.
$21 \sqrt (25c^{2} \times 3c)$
$25c^{2}$ is a perfect square. Square root of $25c^{2}$ is 5c. Because 5c x 5c = $25c^{2}$
$(21)(5c) \sqrt 3c$
$105c \sqrt 3c$
