The value of $a+b+c+d$ if $\left[\begin{array}{ll}2 a+b & a+2 b \\ 2 c+d & c+2 d\end{array}\right]=\left[\begin{array}{ll}8 & 4 \\ 3 & 3\end{array}\right]$ is :
Answer & explanation
Correct answer: option 3
$\left[\begin{array}{cc}2 a+b & a+2 b \\ 2 c+d & c+2 d\end{array}\right]=\left[\begin{array}{ll}8 & 4 \\ 3 & 3\end{array}\right]$
⇒ 2a + b = 8 .....(1)
a + 2b = 4 .....(2)
2c + d = 3 .....(3)
c + 2d = 3 .....(4)
adding (1), (2), (3), (4)
3a + 3b + 3c + 3d = 18
3(a + b + c + d) = 18
a + b + c + d = 6