यदि $2x + 3y - 5z = 7, \,x + y + z = 6$, $3x - 4y + 2z = 1,$ तो $x =$
$\left| {\,\begin{array}{*{20}{c}}2&{ - 5}&7\\1&1&6\\3&2&1\end{array}\,} \right| \div \left| {\,\begin{array}{*{20}{c}}7&3&{ - 5}\\6&1&1\\1&{ - 4}&2\end{array}\,} \right|$
$\left| {\,\begin{array}{*{20}{c}}{ - 7}&3&{ - 5}\\{ - 6}&1&1\\{ - 1}&{ - 4}&2\end{array}\,} \right| \div \left| {\,\begin{array}{*{20}{c}}2&3&{ - 5}\\1&1&1\\3&{ - 4}&2\end{array}\,} \right|$
$\left| {\,\begin{array}{*{20}{c}}7&3&{ - 5}\\6&1&1\\1&{ - 4}&2\end{array}\,} \right| \div \left| {\,\begin{array}{*{20}{c}}2&3&{ - 5}\\1&1&1\\3&{ - 4}&2\end{array}\,} \right|$
इनमें से कोई नहीं
यदि समीकरण निकाय
$2 x+3 y+6 z=8$ ; $x+2 y+a z=5$ ; $3 x+5 y+9 z=b$ का कोई हल नहीं है, तो $a$ और $b$ के मान है
यदि $\Delta_{ r }=\left|\begin{array}{ccc} r & 2 r -1 & 3 r -2 \\ \frac{ n }{2} & n -1 & a \\ \frac{1}{2} n ( n -1) & ( n -1)^{2} & \frac{1}{2}( n -1)(3 n +4)\end{array}\right|$ हैं, तो $\sum_{ r =1}^{ n -1} \Delta_{ r }$ का मान
$\left| {\,\begin{array}{*{20}{c}}1&{\cos (\beta - \alpha )}&{\cos (\gamma - \alpha )}\\{\cos (\alpha - \beta )}&1&{\cos (\gamma - \beta )}\\{\cos (\alpha - \gamma )}&{\cos (\beta - \gamma )}&1\end{array}} \right|$ का मान होगा
यदि $\left| {\,\begin{array}{*{20}{c}}{a + x}&{a - x}&{a - x}\\{a - x}&{a + x}&{a - x}\\{a - x}&{a - x}&{a + x}\end{array}\,} \right| = 0$ तो $x$ के मान होंगे
$\left| {\,\begin{array}{*{20}{c}}1&5&\pi \\{{{\log }_e}e}&5&{\sqrt 5 }\\{{{\log }_{10}}10}&5&e\end{array}\,} \right| = $