Mathematics - Determinant Question with Solution | TestHub

Consider the matrices : $A=\left[\begin{array}{ll}2& -5\\ 3& m\end{array}\right],B=\left[\begin{array}{l}20\\ m\end{array}\right]$ and $X=\left[\begin{array}{l}x\\ y\end{array}\right]$. Let the set of all $m$, for which the system of equations $AX=B$ has a negative solution (i.e., $x<0$ and $y<0$ ), be the interval $(a,b)$. Then $8{\int }_a^b|A|dm$ is equal to_________