线性代数提高线性方程组linear-algebra-1:线性代数:13:第十三章线性方程组:基础题:三-解答题:2:128线性代数做题本（一）解答版解答题不看本题本题讨论已掌握查看解析收入错题#8511设方程组 {2x1+λx2−x3=1,λx1−x2+x3=2,4x1+5x2−5x3=−1,\left\{ \begin{array}{l} 2{x}_{1} + \lambda {x}_{2} - {x}_{3} = 1, \\ \lambda {x}_{1} - {x}_{2} + {x}_{3} = 2, \\ 4{x}_{1} + 5{x}_{2} - 5{x}_{3} = - 1, \end{array}\right.⎩⎨⎧2x1+λx2−x3=1,λx1−x2+x3=2,4x1+5x2−5x3=−1, 问 λ\lambdaλ 为何值时,方程组无解、有唯一解、有无穷多解? 当有无穷多解时,求其通解.