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If `A[{:(3,-4),(1,1),(2,0):}]` and `B=[{:(2,1,2),(1,2,4):}]` and `B=[{:(4,1),(2,3),(1,2):}]` |
Answer» We have, `A=[{:(2,1,2),(1,2,4):}]_(2xx3) "and" B=[{:(4,1),(2,3),(1,2):}]_(3xx2)` So, AB and BA both are possible [since, in both A-B and B-A, the number of columns of first is equal to the number of rows of second] `therefore AB=[{:(2,1,2),(1,2,4):}]_(2xx3)[{:(4,1),(2,3),(1,2):}]_(3xx2)` `=[{:(8+2+2,2+3+4),(4+4+4,1+ 6+8):}]=[{:(12,9),(12,15):}]` and `BA=[{:(4,1),(2,3),(1,2):}]_(3xx2)[{:(2,1,2),(1,2,4):}]_(2xx3)` `= [{:(4xx2+1,4+2,8+4),(4+3,2+ 6,4+12),(2+2,1+4,2+8):}]=[{:(9,6,12),(7,8,16),(4,5,10):}]` |
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