Answer
$0$.
Work Step by Step
The given expression is
$=\sqrt{80x}-5\sqrt{20x}+2\sqrt{45x}$
Factor as a perfect square.
$=\sqrt{4^2\cdot 5x}-5\sqrt{2^2\cdot 5x}+2\sqrt{3^2\cdot 5x}$
Simplify.
$=4\sqrt{ 5x}-5\cdot 2\sqrt{ 5x}+2\cdot 3\sqrt{ 5x}$
Multiply.
$=4\sqrt{ 5x}-10\sqrt{ 5x}+6\sqrt{ 5x}$
Use the distributive property.
$=(4-10+6)\sqrt{ 5x}$
Simplify.
$=0$.
