\(\left\{ \begin{array}{l}{u_2} - 3{u_4} + {u_7} =  - 1\\{u_3} + {u_5} + {u_6} = 18\end{array} \right.\)
A.\({u_1} =  - 5,\,\,d = 3\)
B.\({u_1} =  - 5,\,\,d =- 3\)
C.\({u_1} =  5,\,\,d = 3\)
D.\({u_1} =  5,\,\,d =- 3\)

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