If $\begin{bmatrix}x-y&t\\2x-y&w\end{bmatrix}=\begin{bmatrix}-1&2\\0&1\end{bmatrix}$, then $2x + y + 3t+ w$ is equal to |
9 11 12 10 |
11 |
The correct answer is Option (2) → 11 ** $\begin{pmatrix}x-y & t\\ 2x-y & w\end{pmatrix} =\begin{pmatrix}-1 & 2\\ 0 & 1\end{pmatrix}$ $x-y=-1,\quad t=2$ $2x-y=0,\quad w=1$ Subtracting the first two equations: $(2x-y)-(x-y)=0-(-1)$ $x=1$ $x-y=-1\;\Rightarrow\;1-y=-1\;\Rightarrow\;y=2$ Now evaluate: $2x+y+3t+w=2(1)+2+3(2)+1$ $=2+2+6+1$ $=11$ The required value is $11$. |