Answer
$\frac{-28x^2}{3}*\sqrt {x}$
Work Step by Step
$-2*\sqrt {7x^2} *\frac{1}{3}\sqrt {28x^3}$
$\frac{-2}{3}*x\sqrt 7*\sqrt {2*2*7*x^2*x}$
$\frac{-2}{3}*x\sqrt 7*2x\sqrt{7x}$
$\frac{-2}{3}*2x^2\sqrt {49x}$
$\frac{-4x^2}{3}*\sqrt {7*7x}$
$\frac{-28x^2}{3}*\sqrt {x}$
