Question 993752
I'm really having a tough time with this problem, can you help me?
here is the problem:
{{{6sqrt(12)}}}-{{{8sqrt(50)}}}+{{{9sqrt(72)}}}

I rewrote it using prime factorization and got this:
{{{6*2sqrt(3)}}}-{{{8*5sqrt(2)}}}+{{{9*3*2sqrt(2)}}}

I simplified to this:
{{{12sqrt(3)}}}-{{{40sqrt(2)}}}+{{{54sqrt(2)}}}

I tried to solve this and got {{{12sqrt(3)}}}+{{{14sqrt(2)}}} but the answer key shows the answer as: {{{57sqrt(3)}}}-{{{40sqrt(2)}}} Can you tell me how they got that? 
<pre>Your answer is correct.
For the answer key to be correct, the problem would have to be: {{{6sqrt(12)}}}-{{{8sqrt(50)}}}+{{{highlight_green(9sqrt(75))}}}, as opposed to: {{{6sqrt(12)}}}-{{{8sqrt(50)}}}+{{{highlight_green(9sqrt(72))}}}
It may've been {{{highlight_green(sqrt(75))}}}, and not {{{highlight_green(sqrt(72))}}}. Check the problem!! Maybe you copied it incorrectly!