$k$ ની કઈ કિંમત માટે નીચે આપેલ સુરેખ સમીકરણોની જોડને કોઈ ઉકેલ નથી?
$3x + y = 1$
$(2k - 1)x + (k - 1)y = 2k + 1$

Which of the following pairs of linear equations has a unique solution,no solution,or infinitely many solutions? In case there is a unique solution,find it by using the cross-multiplication method.
$2x + y = 5$
$3x + 2y = 8$

Check graphically whether the pair of equations
$x+3y=6$ $...(1)$
and $2x-3y=12$ $...(2)$
is consistent. If so,solve them graphically.

Draw the graphs of the equations $x-y+1=0$ and $3x+2y-12=0$. Determine the coordinates of the vertices of the triangle formed by these lines and the $x$-axis,and shade the triangular region.

Solve the following pair of linear equations by the substitution method.
$s-t=3$
$\frac{s}{3}+\frac{t}{2}=6$

On comparing the ratios $\frac{a_{1}}{a_{2}}, \frac{b_{1}}{b_{2}}$ and $\frac{c_{1}}{c_{2}},$ find out whether the following pair of linear equations are consistent or inconsistent.
$3x + 2y = 5; \quad 2x - 3y = 7$