Question

me ajudem por favor!!!!​

Answer 1

Ora,

$\begin{bmatrix}x+ y & 2\\3 & 1\end{bmatrix} = \begin{bmatrix}4 & x-y\\3 & 1\end{bmatrix}\\\\\begin{cases}x+y = 4\\x-y = 2\end{cases}\\\\x = 3\\y=1$

Letra a