Answer
$-20$.
Work Step by Step
The given expression is
$=5\left (\frac{\sqrt{81}}{3} -7\right )$
Use $81=9^2$.
$=5\left (\frac{\sqrt{9^2}}{3} -7\right )$
Evaluate the square root.
$=5\left (\frac{9}{3} -7\right )$
Divide.
$=5\left (3 -7\right )$
Subtract.
$=5\left (-4\right )$
Multiply.
$=-20$.
