Simplify 3(sqrt)6+5(sqrt)54 by Adding Radicals

[math_fanatic]

Okay this is what I've done based off what I was shown:

3(sqrt)6+5(sqrt)54
3(sqrt)2x?3 +5(sqrt)2x(sqrt)3^2x(sqrt)3
8(sqrt)3+3+3 (This is where I get confused)
8(sqrt)3+6

I tried to calculate the answer on my calculator and they get 44.09. The work I showed calculates to 19.85. Could someone show me where I went wrong? From what I'm looking at I messed up after the second step. I may have even messed up on the second step.

 

[Unco]

Okay this is what I've done based off what I was shown:

3(sqrt)6+5(sqrt)54
3*sqrt(2*3) + 5*sqrt(2)*sqrt(3^2)*sqrt(3)
8(sqrt)3+3+3 (This is where I get confused)
You haven't shown how you arrived at this from the second line.
8(sqrt)3+6

Consider an approach such as
\(\displaystyle \mbox{ 3\sqrt{6} + 5\sqrt{54} = 3\sqrt{6} + 15\sqrt{6} = 18\sqrt{6}}\)