in entry matrix first two raw is exchange with another matrix which is 2*3 replace first two whole raw with that

         entry matrix
          1.00          4.00          4.00
          3.00             0          6.00
          5.00          3.00          1.00
          5.00             0          4.00
             0          3.00          6.00
          2.00          1.00          6.00

another matrix C

1 0 9
4 6 9

now first two row of entry matrix is remove with c entry matrix is now seen like this

1 0 9
4 6 9 
5 3 1
5 0 4
0 3 6
2 1 6

Answer 1

[KSSV]

em = [1.00          4.00          4.00
          3.00             0          6.00
          5.00          3.00          1.00
          5.00             0          4.00
             0          3.00          6.00
          2.00          1.00          6.00] ;
c = [1 0 9
4 6 9] ;      
iwant = em ;
iwant(1:2,:) = c(1:2,:) ;