Question

Exercício sobre matriz.

Answer 1

Explicação passo-a-passo:

Seja $\sf X=\left[\begin{array}{c} \sf a \\ \sf b\end{array}\right]$

Temos que:

$\sf X\cdot\left[\begin{array}{ccc} \sf 1 &\sf 2&\sf 3\end{array}\right]=\left[\begin{array}{ccc} \sf 2&\sf 4&\sf 6 \\ \sf 1&\sf 2&\sf 3\end{array}\right]$

$\sf \left[\begin{array}{c} \sf a \\ \sf b\end{array}\right]\cdot\left[\begin{array}{ccc} \sf 1 &\sf 2&\sf 3\end{array}\right]=\left[\begin{array}{ccc} \sf 2&\sf 4&\sf 6 \\ \sf 1&\sf 2&\sf 3\end{array}\right]$

$\sf \left[\begin{array}{ccc} \sf a &\sf 2a &\sf 3a \\ \sf b &\sf 2b &\sf 3b\end{array}\right]=\left[\begin{array}{ccc} \sf 2 &\sf 4 &\sf 6 \\ \sf 1&\sf 2 &\sf 3\end{array}\right]$

Assim:

$\sf a=2$

$\sf b=1$

Logo, $\sf X=\left[\begin{array}{c} \sf 2\\ \sf 1\end{array}\right]$