设向量组 $\boldsymbol{\alpha}_{1}, \boldsymbol{\alpha}_{2}, \boldsymbol{\alpha}_{3}$ 线性相关, 向量组 $\boldsymbol{\alpha}_{2}, \boldsymbol{\alpha}_{3}, \boldsymbol{\alpha}_{4}$ 线性无关, 问:
(1) $\boldsymbol{\alpha}_{1}$ 能否由 $\boldsymbol{\alpha}_{2}, \boldsymbol{\alpha}_{3}$ 线性表出? 证明你的结论.
(2) $\boldsymbol{\alpha}_{4}$ 能否由 $\boldsymbol{\alpha}_{1}, \boldsymbol{\alpha}_{2}, \boldsymbol{\alpha}_{3}$ 线性表出?证明你的结论.