设 $A = (\pmb{\alpha}_1, \pmb{\alpha}_2, \pmb{\alpha}_3)$ 为 3 阶矩阵. 若 $\pmb{\alpha}_1, \pmb{\alpha}_2$ 线性无关，且 $\pmb{\alpha}_3 = -\pmb{\alpha}_1 + 2\pmb{\alpha}_2$ ，则线性方程组 $Ax = 0$ 的通解为