Question

São dadas as matrizes A = (aij) e B = (bij), quadradas de ordem 2, com aij = 3i - 4j e bij = – 4i + 3j. Considerando C = A x B, calcule a matriz C.​

Answer 1

$\Large\boxed{\begin{array}{l}\sf a_{11}=3\cdot1-4\cdot1=-1\\\sf a_{12}=3\cdot1-4\cdot2=-5\\\sf a_{21}=3\cdot2-4\cdot1=2\\\sf a_{22}=3\cdot2-4\cdot2=-2\\\sf A=\begin{bmatrix}\sf-1&\sf-5\\\sf2&\sf-2\end{bmatrix}\\\sf b_{11}=-4\cdot1+3\cdot1=-1\\\sf b_{12}=-4\cdot1+3\cdot2=2\\\sf b_{21}=-4\cdot2+3\cdot1=-5\\\sf b_{22}=-4\cdot2+3\cdot2=-2\\\sf B=\begin{bmatrix}\sf-1&\sf2\\\sf-5&\sf-2\end{bmatrix}\end{array}}$

$\Large\boxed{\begin{array}{l}\sf C=\begin{bmatrix}\sf-1&\sf-5\\\sf2&\sf-2\end{bmatrix}\cdot\begin{bmatrix}\sf-1&\sf2\\\sf-5&\sf-2\end{bmatrix}\\\\\sf C=\begin{bmatrix}\sf-1\cdot(-1)-5\cdot(-5)&\sf-1\cdot2-5\cdot(-2)\\\sf2\cdot(-1)-2\cdot(-5)&\sf2\cdot2-2\cdot(-2)\end{bmatrix}\\\\\sf C=\begin{bmatrix}\sf26&\sf8\\\sf8&\sf8\end{bmatrix}\end{array}}$

Answer 2

Resposta:

sera que anho 20 pontos nesse tbm ?