Express the Vector X as a Linear Combination of the Uʹs

Multiple Choice

Express the vector x as a linear combination of the uʹs.
- $\mathbf { u } _ { 1 } = \left[ \begin{array} { r } - 2 \\ 0 \\ 1 \end{array} \right] , \mathbf { u } _ { 2 } = \left[ \begin{array} { l } 3 \\ 5 \\ 6 \end{array} \right] , \mathbf { u } _ { 3 } = \left[ \begin{array} { r } - 2 \\ 6 \\ - 4 \end{array} \right] , \mathbf { x } = \left[ \begin{array} { r } 9 \\ 39 \\ - 2 \end{array} \right]$

A) $\mathbf { x } = 4 \mathbf { u } _ { 1 } + 6 \mathbf { u } _ { 2 } - 4 \mathbf { u } _ { 3 }$
B) $\mathbf { x } = 4 \mathbf { u } _ { 1 } - 3 \mathbf { u } _ { 2 } - 4 \mathbf { u } _ { 3 }$
C) $\mathbf { x } = - 8 \mathbf { u } _ { 1 } + 6 \mathbf { u } _ { 2 } + 8 \mathbf { u } _ { 3 }$
D) $\mathbf { x } = - 4 \mathbf { u } _ { 1 } + 3 \mathbf { u } _ { 2 } + 4 \mathbf { u } _ { 3 }$