Answer:
The answer simplifies to zero
Step-by-step explanation:
3 sqrt(128) - 2 sqrt(6) * 4 sqrt(3)
3 sqrt(128) - 8 sqrt(6*3)
3sqrt(128) - 8 sqrt(18)
3 sqrt(64*2) - 8 sqrt(9*2)
3 sqrt(64)sqrt(2) - 8 sqrt(9) sqrt(2)
3 * 8 * sqrt(2) - 8 * 3 * sqrt(2)
24 sqrt(2) - 24 sqrt(2)
0