求解方程组:<br/>{3x<sub>1</sub>+4x<sub>2</sub>-6x<sub>3</sub>=4<br/>{x<sub>1</sub>-x<sub>2</sub>+4x<sub>3</sub>=1<br/>{-x<sub>1</sub>+3x<sub>2</sub>-10x<sub>3</sub>=1

题目类型: 问答题

题目内容

求解方程组:
{3x1+4x2-6x3=4
{x1-x2+4x3=1
{-x1+3x2-10x3=1

正确答案

方程组的增广矩阵为 (A,β)= (3 4 -6 ┆ 4 1 -1 4 ┆ 1 -1 3 -10 ┆ 1) 对增广矩阵作初等变换得 (A,β)= (3 4 -6 ┆ 4 1 -1 4 ┆ 1 -1 3 -10 ┆ 1) → (1 -1 4 ┆ 1 3 4 -6 ┆ 4 -1 3 -10 ┆ 1) → (1 -1 4 ┆ 1 0 7 -18 ┆ 1 0 2 -6 ┆ 2) → (1 -1 4 ┆ 1 0 1 -3 ┆ 1 0 7 -18┆ 1) → (1 -1 4 ┆ 1 0 1 -3 ┆ 1 0 0 3 ┆ -6) → (1 0 0 ┆ 4 0 1 0 ┆ -5 0 0 1 ┆ -2) 因此方程组的解为x1=4,x2=-5,x3=-2.

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