The ordered pair $(a, b)$, for which the system of linear equations  $3 x-2 y+z=b$  ;  $5 x-8 y+9 z=3$  ;  $2 x+y+a z=-1$ has no solution, is

$2x + 3y + 4z = 9$,$4x + 9y + 3z = 10,$$5x + 10y + 5z = 11$ then the value of $ x$ is

If $\left| {\begin{array}{*{20}{c}}{a\, + \,1}&{a\, + \,2}&{a\, + \,p}\\{a\, + \,2}&{a\, +\,3}&{a\, + \,q}\\{a\, + \,3}&{a\, + \,4}&{a\, + \,r}\end{array}} \right|$ $= 0$ , then $p, q, r$ are in :

A root of the equation $\left| {\,\begin{array}{*{20}{c}}{3 – x}&{ – 6}&3\\{ – 6}&{3 – x}&3\\3&3&{ – 6 – x}\end{array}\,} \right| = 0$ is

The value of the determinant$\left| {\,\begin{array}{*{20}{c}}1&1&1\\1&{1 – x}&1\\1&1&{1 + y}\end{array}\,} \right|$is