Compare two matrix and delete the same rows

Say I have A= [1 2 3, 4 5 6, 6 7 8] and B= [4 5 7, 1 2 3, 7 6 4, 6 7 8]. How can I delete the rows in B that are the same with A? The result desired is B=[4 5 7, 7 6 4]

Thanks!

Answer 1

[Azzi Abdelmalek]

A= [1 2 3; 4 5 6; 6 7 8] 
B= [4 5 7; 1 2 3; 7 6 4; 6 7 8]
B(ismember(B,A,'rows'),:)=[]

Answer 2

[Andrei Bobrov]

setdiff(B,A,'rows')

Answer 3

[David Sanchez]

A= [1 2 3; 4 5 6; 6 7 8];
B= [4 5 7; 1 2 3; 7 6 4; 6 7 8];

Lia = ismember(B,A,'rows');

B_new = B(~Lia,:)

B_new =

       4     5     7
       7     6     4