How to simplify this? What did I do wrong? $$(3-\sqrt3) (2-\sqrt3)-\sqrt3\cdot\sqrt{27}.$$
So I simplified the $\sqrt3\cdot\sqrt{27}$ part into 
$$\sqrt 3\cdot\sqrt{9\cdot3} = \sqrt3\cdot3\cdot\sqrt3=4\cdot\sqrt3$$
Then I multiplied the brackets :
$$6+\sqrt3-2\cdot\sqrt3-3\cdot\sqrt3 =6-4\cdot\sqrt3.$$
Then minus the $4\cdot\sqrt3$ we got 
$$6-8\cdot\sqrt3$$ 
However the answer should be $-5\cdot\sqrt3$
How can I get that answer, what did I do wrong?

Second line, second equal sign is wrong.
$\sqrt{3}\cdot 3 \cdot \sqrt{3} = 9$
Multiplying the brackets yelds:
$6 - 2\sqrt{3} - 3\sqrt{3} +3 = 9 - 5\sqrt{3}$
Putting it all together:
$9 - 5\sqrt{3} - 9 = -5\cdot \sqrt{3}$
