Cho hệ phương trình \[\left\{ \begin{array}{l}x - 7y = m\\ - mx + 2y = 9\end{array} \right..\] Khi \[m = 1\] thì hệ phương trình đã cho có nghiệm là

A. \[\left\{ \begin{array}{l} - x + 4y = 0\\3x - 2y = 10.\end{array} \right.\]

B. \[\left\{ \begin{array}{l}{x^2} - 5{y^2} = 2\\3y = 4.\end{array} \right.\]

C. \[\left\{ \begin{array}{l}0x + 0y = - 5\\4x - 7y = - 8.\end{array} \right.\]

D. \[\left\{ \begin{array}{l}2x = - 7\\x + \frac{1}{y} = 6.\end{array} \right.\]

A. \[2x + 3y = - 5.\]

B. \[0x - 7y = 1.\]

C. \[0x + 0y = 2.\]

D. \[4x - 0y = 11.\]

A. \[2x + y = 2.\]

B. \[2x - y = - 7.\]

C. \[x - 3y = - 10.\]

D. \[x - y = 1.\]

A. \[y = 2x - 3.\]

B. \[y = - 2x + 3.\]

C. \[y = 3x + 2.\]

D. \[y = 4x - 6.\]

A. \[a = 2,\,\,b = - 4,\,\,c = 1.\]

B. \[a = 2,\,\,b = 4,\,\,c = - 1.\]

C. \[a = - 4,\,\,b = 2,\,\,c = - 1.\]

D. \[a = 2,\,\,b = - 4,\,\,c = - 1.\]

A. \[\left\{ \begin{array}{l}x + y = - 1\\y - 2x = 5.\end{array} \right.\]

B. \[\left\{ \begin{array}{l}x + y = 1\\2x - y = 5.\end{array} \right.\]

C. \[\left\{ \begin{array}{l}x + y = - 1\\2x - y = 7.\end{array} \right.\]

D. \[\left\{ \begin{array}{l}x + y = 1\\2x - y = 7.\end{array} \right.\]

A. \[\left\{ \begin{array}{l}x + y = 155\\ - 5x + y = 17\end{array} \right..\]

B. \[\left\{ \begin{array}{l}x + y = 155\\x - 5y = 17\end{array} \right..\]

C. \[\left\{ \begin{array}{l}x + y = 155\\5x + y = 17\end{array} \right..\]

D. \[\left\{ \begin{array}{l}x + y = 155\\5x - y = 17\end{array} \right..\]