Question
Consider the system of linear equations;
$$\eqalign{
& {x_1} + 2{x_2} + {x_3} = 3 \cr
& 2{x_1} + 3{x_2} + {x_3} = 3 \cr
& 3{x_1} + 5{x_2} + 2{x_3} = 1 \cr} $$
The system has
A.
exactly 3 solutions
B.
a unique solution
C.
no solution
D.
infinite number of solutions
Answer :
no solution
Solution :
\[D = \left| \begin{array}{l}
1\,\,\,\,\,\,\,2\,\,\,\,\,\,1\\
2\,\,\,\,\,\,3\,\,\,\,\,\,1\\
3\,\,\,\,\,\,5\,\,\,\,\,\,2
\end{array} \right| = 0\,\,\,\,\,\,\,{D_1} = \left| \begin{array}{l}
3\,\,\,\,\,\,2\,\,\,\,\,\,1\\
3\,\,\,\,\,\,3\,\,\,\,\,\,1\\
1\,\,\,\,\,\,5\,\,\,\,\,\,2
\end{array} \right| \ne 0\]
⇒ Given system, does not have any solution.
⇒ No solution