The sum of the digits of a two-digit number is $6$. If the digit at the unit's place is twice the digit at the ten's place,then that number is..........

The pair of equations $5x - 15y = 8$ and $3x - 9y = \frac{24}{5}$ has

$A$ two-digit number is obtained by either multiplying the sum of the digits by $8$ and then subtracting $5$,or by multiplying the difference of the digits by $16$ and then adding $3$. Find the number.

............ is not a linear equation in two variables.

Find the value of $k$ for which the following pair of linear equations has infinitely many solutions:
$kx + 3y = k - 3$
$12x + ky = k$

If $\frac{x}{2} = \frac{6}{y} = 2$,then the value of $x - y$ is ..........