$(-1, 3)$ is not a solution of the equation $\ldots \ldots \ldots \ldots$

If the following pair of equations is consistent (unique solution),then find the value of $k$:
$x - ky = 2$
$3x + 2y = -5$

Solve the following pair of linear equations by the substitution and cross-multiplication methods:
$8x + 5y = 9$
$3x + 2y = 4$

Formulate the following problems as a pair of equations,and hence find their solutions:
Roohi travels $300 \ km$ to her home partly by train and partly by bus. She takes $4 \ hours$ if she travels $60 \ km$ by train and the remaining by bus. If she travels $100 \ km$ by train and the remaining by bus,she takes $10 \ minutes$ longer. Find the speed of the train and the bus separately.

The students of a class are made to stand in rows. If $3$ students are extra in a row,there would be $1$ row less. If $3$ students are less in a row,there would be $2$ rows more. Find the number of students in the class.

Solve the following pairs of equations:
$43x + 67y = -24$
$67x + 43y = 24$