Question

1 – Escrevendo a matriz A = (ai j )1 x 3, tal que ai j = 3.i – 2.j , encontraremos a matriz: (a) A = [ -1 1 3 ] (b) A = [ 1 1 - 3 ] (e) [ 1 1 1 ] (c) A = [ 1 -1 – 3 ] (d) A = [ - 3 -1 1 ]​

Answer 1

$\large\boxed{\begin{array}{l}\sf A=(a_{ij})_{1\times 3},a_{ij}=3\cdot i-2\cdot j\\\\\sf A=\begin{bmatrix}\sf a_{11} &\sf a_{12}&\sf a_{13}\end{bmatrix}\\\sf a_{11}=3\cdot1-2\cdot1=3-2=1\\\sf a_{12}=3\cdot1-2\cdot2=3-4=-1\\\sf a_{13}=3\cdot1-2\cdot3=3-6=-3\\\sf A=\begin{bmatrix}\sf1&\sf-1&\sf-3\end{bmatrix}\\\huge\boxed{\boxed{\boxed{\boxed{\sf\dagger\red{\maltese}~\blue{alternativa~c}}}}}\end{array}}}$