Hãy chọn câu trả lời đúng nhất:

A. \[\left\{ {{{\rm{u}}_1} = ( - 2,1, - 1),{{\rm{u}}_2} = (1, - 1, - 1),{{\rm{u}}_3} = ( - 1,0, - 2)} \right\}\]

B. \[\left\{ {{{\rm{u}}_1} = (1,1,2),{{\rm{u}}_2} = (1, - 1, - 1),{{\rm{u}}_3} = (2,1,1)} \right\}\]

C. \[\left\{ {{{\rm{u}}_1} = (1,1);{{\rm{u}}_2} = ( - 1,1),{{\rm{u}}_3} = (2,1,1)} \right\}\]

D. \[\left\{ {{{\rm{u}}_1} = (1,1,0);{{\rm{u}}_2} = (0,1,0),{{\rm{u}}_3} = (0,0,1)} \right\}\]

A. m = 0

B. m = -1

C. m = 2

D. Đáp án khác

A. \[\left\{ {{{\rm{u}}_1} = (1,1,2);{{\rm{u}}_2} = (1, - 1, - 1),{{\rm{u}}_3} = (0,0,0)} \right\}\]

B. \[\left\{ {{{\rm{u}}_1} = ( - 2,1, - 1,1);{{\rm{u}}_2} = (1, - 1, - 1,2),{{\rm{u}}_3} = ( - 1,0, - 2,1)} \right\}\]

C. \[\left\{ {{{\rm{u}}_1} = ( - 2,1, - 1);{{\rm{u}}_2} = (1, - 1, - 1),{{\rm{u}}_3} = ( - 1,0, - 2)} \right\}\]

D. \[\left\{ {{{\rm{u}}_1} = (1,1);{{\rm{u}}_2} = (1, - 1)} \right\}\]

A. Với mọi m

B. m = 1

C. m = 3

D. \[{\rm{m}} \ne - 3\]

A. \[({\rm{p}} \wedge ({\rm{p}} \Rightarrow {\rm{q}})) \equiv {\rm{q}}\]

B. \[(\overline {{\rm{p}} \Rightarrow {\rm{q}})} \equiv ({\rm{p}} \wedge \overline {{\rm{q}})} \]

C. \[({\rm{p}} \Rightarrow {\rm{q}}) \wedge ({\rm{p}} \Rightarrow {\rm{r}})) \equiv ({\rm{p}} \Rightarrow {\rm{r}})\]

D. Tất cả các ý trên đều đúng

A. m = 0

B. m = −1

C. \[{\rm{m}} \ne 0, - 1\]

D. \[\forall {\rm{m}} \in {\rm{R}}\]