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3 and 4 .Determinants and Matrices
hard
સમીકરણની સંહતિ ${x_1} - {x_2} + {x_3} = 2,$ $\,3{x_1} - {x_2} + 2{x_3} = - 6$ અને $3{x_1} + {x_2} + {x_3} = - 18$ નો ઉકેલ . . . .
A
ખાલીગણ
B
એકાકી ઉકેલ
C
અનંત ઉકેલ
D
એકપણ નહી.
Solution
(c) $D = \left| {\,\begin{array}{*{20}{c}}1&{ – 1}&1\\3&{ – 1}&2\\3&1&1\end{array}\,} \right|\, = \,1[ – 1 – 2] – 1[6 – 3] + 1[3 + 3] = 0$
and${D_1} = \left| {\,\begin{array}{*{20}{c}}2&{ – 1}&1\\{ – 6}&{ – 1}&2\\{ – 18}&1&1\end{array}\,} \right|\, = 2( – 1 – 2) – 1( – 36 + 6) + 1( – 6 – 18)$
${D_1} = – 6 + 30 – 24 = 0$
Also, ${D_2} = 0;\,{D_3} = 0$
So the system is consistent $(D = {D_1} = {D_2} = {D_3} = 0)$
i.e. system has infinite solution.
Standard 12
Mathematics