$x$ is larger in two numbers $x$ and $y$. Two times the larger number is $4$ more than five times the smaller number. The equation form of this data is $\ldots \ldots \ldots \ldots$

For the linear equation in two variables $2x - 5y = 3$,if $y = -1$,then $x = \ldots$

$A$ boat goes $32 \, km$ upstream and $36 \, km$ downstream in $7$ hours. In $9$ hours,it can go $40 \, km$ upstream and $48 \, km$ downstream. Determine the speed of the stream and that of the boat in still water. (Speed of boat in still water is more than the speed of the stream of river.)

Draw the graphs of the equations $2x + 3y = 8$ and $x + 2y = 5$ on the same graph paper. Find the solution of the system from the graph.

Solve the following pair of linear equations by the method of substitution: $x + 11y = 1$ and $8x + 13y = 2$.

Solve the following pairs of equations by the cross-multiplication method:
$x - 3y = -5$
$3x = 7y - 13$