The solution set of $x+y-3=0$ and $3x+3y-9=0$ is ............

From the pair of equations $x + 2y = 8 \dots(1)$ and $3x - 4y = -6 \dots(2)$,the first equation should be multiplied by ............. to eliminate $y$.

Draw the graphs of the pair of linear equations $x+y=10$ and $x-y=4$. Determine the coordinates of the vertices of the triangle formed by these linear equations and the $X$-axis.

The solution set of a pair of equations $5x - 5y = -5$ and $\frac{3x}{2} - \frac{3y}{2} + \frac{3}{2} = 0$ is.........

$A$ motor boat can travel $30 \, km$ upstream and $28 \, km$ downstream in $7 \, hours$. It can travel $21 \, km$ upstream and return in $5 \, hours$. Find the speed of the boat in still water and the speed of the stream (in $km/h$).

Solve the following pair of linear equations by the method of elimination: $2x + 5y = 7$ and $4x + 10y = 12$.