Two questions, 100 points, will mark

1. 0

2.  see below

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

2.  5 is rational

-3sqrt(8) = -3 sqrt(4) sqrt(2) = -3 * 2 sqrt(2) = -6 sqrt(2)  is irrational

addition:  when you add a rational plus an irrational, you get an irrational

5 + -6 sqrt(2) = irrational

subtraction : when you subtract a ration and an irrational, you get an irrational

5 - -6 sqrt (2) = 5 + 6 sqrt(2)   = irrational

multiplication:   when you multiply a rational and an irrational, you get an irrational

5 * -6sqrt(2) = -30 sqrt(2) = irrational

division:  when you divide a rational by an irrational, you will get an irrational

i dont know it

step-by-step explanation: