题目 Problem M=(3x74x+12−x)\mathbf{M} = \begin{pmatrix} 3x & 7 \\ 4x + 1 & 2 - x \end{pmatrix}M=(3x4x+172−x) Find the range of values of xxx for which the determinant of the matrix M\mathbf{M}M is positive. (5) 题目中文翻译 M=(3x74x+12−x)\mathbf{M} = \begin{pmatrix} 3x & 7 \\ 4x + 1 & 2 - x \end{pmatrix}M=(3x4x+172−x) 求使矩阵 M\mathbf{M}M 的行列式为正值的 xxx 的取值范围。 解答
