Question

Efetue a somas das matrizes quadradas conforme o que se pede:

a- A + B
B- b+ C
C- a+ C
d- A + B + C

Answer 1

$\large\boxed{\begin{array}{l}\boldsymbol{Resposta:}\\\tt a)~\begin{vmatrix}\sf-6&\sf-6&\sf12\\\sf8&\sf11&\sf11\\\sf12&\sf13&\sf12\end{vmatrix}\\\\\tt b)~\begin{vmatrix}\sf-5&\sf-5&\sf5\\\sf18&\sf13&\sf6\\\sf10&\sf15&\sf11\end{vmatrix}\\\\\tt c)~\begin{vmatrix}\sf3&\sf5&\sf-1\\\sf2&\sf12&\sf7\\\sf6&\sf14&\sf15\end{vmatrix}\\\\\tt d)~\begin{vmatrix}\sf-4&\sf-3&\sf8\\\sf14&\sf18&\sf12\\\sf14&\sf21&\sf19\end{vmatrix}\\\boldsymbol{Explicac_{\!\!,}\tilde ao~passo~a~passo:}\end{array}}$

$\boxed{\begin{array}{l}\tt a)~\sf A+B=\begin{vmatrix}\sf1-7&\sf2-8&\sf3+9\\\sf-4+12&\sf5+6&\sf6+5\\\sf4+8&\sf6+7&\sf8+4\end{vmatrix}=\begin{vmatrix}\sf-6&\sf-6&\sf12\\\sf8&\sf11&\sf11\\\sf12&\sf13&\sf12\end{vmatrix}\end{array}}$

$\boxed{\begin{array}{l}\tt b)~\sf B+C=\begin{vmatrix}\sf-7+2&\sf-8+3&\sf9-4\\\sf12+6&\sf6+7&\sf5+1\\\sf8+2&\sf7+8&\sf4+7\end{vmatrix}=\begin{vmatrix}\sf-5&\sf-5&\sf5\\\sf18&\sf13&\sf6\\\sf10&\sf15&\sf11\end{vmatrix} \end{array}}$

$\boxed{\begin{array}{l}\tt c)~\sf A+C=\begin{vmatrix}\sf1+2&\sf2+3&\sf3-4\\\sf-4+6&\sf5+7&\sf6+1\\\sf 4+2&\sf6+8&\sf8+7\end{vmatrix}=\begin{vmatrix}\sf3&\sf5&\sf-1\\\sf2&\sf12&\sf7\\\sf6&\sf14&\sf15\end{vmatrix}\end{array}}$

$\boxed{\begin{array}{l}\tt d)~\sf A+B+C=\begin{vmatrix}\sf1-7+2&\sf2-8+3&\sf3+9-4\\\sf-4+12+6&\sf5+6+7&\sf6+5+1\\\sf4+8+2&\sf6+7+8&\sf8+4+7\end{vmatrix}=\begin{vmatrix}\sf-4&\sf-3&\sf8\\\sf14&\sf18&\sf12\\\sf14&\sf21&\sf19\end{vmatrix}\end{array}}$