Question:
Find the value of k for which the system has
(i) a unique solution
(ii) no solution.
$k x+2 y=5$
$3 x+y=1$
Solution:
GIVEN:
$k x+2 y=5$
$3 x+y=1$
To find: To determine for what value of k the system of equation has
(1) Unique solution
(2) No solution
We know that the system of equations
$a_{1} x+b_{1} y=c_{1}$
$a_{2} x+b_{2} y=c_{2}$
(1) For Unique solution
$\frac{a_{1}}{a_{2}} \neq \frac{b_{1}}{b_{2}}$
Here,
$\frac{k}{3} \neq \frac{2}{1}$
$k \neq 6$
Hence for $k \neq 6$ the system of equation has unique solution.
(2) For no solution
$\frac{a_{1}}{a_{2}}=\frac{b_{1}}{b_{2}} \neq \frac{c_{1}}{c_{2}}$
$\frac{k}{3}=\frac{2}{1} \neq \frac{5}{1}$
$k=6$
Hence for $k=6$ the system of equation has no solution