Q$2)$ In the liquid$-$level system shown below, the tanks $1$ and $2$ are connected to each other, have liquid heights of $h_1$ and $h_2,$ and cross$-$sectional areas of $A_1$ and $A_2.$ The fluid density is constant and equal to $.$

$($a$)$ Determine a mathematical model $($differential equation$)$ in $h,$

$($b$)$ Put the system equations in matrix form.