The rank of the matrix A = \(\left[ {\begin{array}{*{20}{c}} 1&2\\ 9&5\\ 7&1 \end{array}\;\;\;\;\begin{array}{*{20}{c}} 1&{ - 1}\\ 2&2\\ 0&4 \end{array}} \right]\) is _____.

The rank of the matrix A = \(\left[ {\begin{array}{*{20}{c}} 1&2\\ 9&

1.	The rank of the matrix A = \(\left[ {\begin{array}{{20}{c}} 1&2\\ 9&5\\ 7&1 \end{array}\;\;\;\;\begin{array}{{20}{c}} 1&{ - 1}\\ 2&2\\ 0&4 \end{array}} \right]\) is _____.
A.	0
B.	1
C.	2
D.	3
Answer» D. 3