(2 sqrt6 - 4 sqrt3)(4 sqrt6 + 8 sqrt3)
I used the FOIL method
2sqrt6 * 4sqrt6 + 2sqrt6 * 8sqrt3 - 4sqrt3 * 4sqrt6 - 4sqrt3 * 8sqrt3
12sqrt36 - 32sqrt9
I got alittle stuck here but I then I realized what the next step was
12 * 6 - 32 * 3
72 - 96
-24
If this is correct I think I am on the right track...Thanks