1. Escribe explícitamente la matriz A :A = [a ij] 2 x 3 Si : aij = 3 ; i = j aij = i + j ; i ≠ j2?

1. <img src="https://tex.z-dn.net/?f=%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D%0A3%263%264%5C%5C%0A3%263%265%5C%5C%0A%5Cend%7Barray%7D%5Cright%5D%20" />

Las otras no se entienden

utiliza dentro de LaTeX \ left[ \ begin{array}{ccc}

3&3&4 \ \

3&3&5 \ \ \ end{array} \ right]

cada \ \ representa un cambio de línea, & separa cada columna

6.

Puedes resolverla por cramer

<img src="https://tex.z-dn.net/?f=M%3D%20%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%261%5C%5C2%26-1%261%5C%5C1%261%26-2%5Cend%7Barray%7D%5Cright%5D%5C%5C%0A%5Cdet%20M%20%3D%209" />

luego identificas las demás

<img src="https://tex.z-dn.net/?f=M_x%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D12%261%261%5C%5C4%26-1%261%5C%5C-3%261%26-2%5Cend%7Barray%7D%5Cright%5D%5C%5C%0A%5Cdet%20M_x%3D18" />

<img src="https://tex.z-dn.net/?f=M_y%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%2612%261%5C%5C2%264%261%5C%5C1%26-3%26-2%5Cend%7Barray%7D%5Cright%5D%5C%5C%0A%5Cdet%20M_y%20%3D%2045" />

<img src="https://tex.z-dn.net/?f=M_z%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%2612%5C%5C2%26-1%264%5C%5C1%261%26-3%5Cend%7Barray%7D%5Cright%5D%5C%5C%0A%5Cdet%20M_z%20%3D%2045" />

entonces

<img src="https://tex.z-dn.net/?f=%24x%3D%5Cfrac%7B%7CM_x%7C%7D%7B%7CM%7C%7D%20%3D%2018%2F9%20%3D%202%24" />

<img src="https://tex.z-dn.net/?f=%24y%3D%5Cfrac%7B%7CM_y%7C%7D%7B%7CM%7C%7D%3D45%2F9%3D5%24" />

<img src="https://tex.z-dn.net/?f=%24z%3D%5Cfrac%7B%7CM_z%7C%7D%7B%7CM%7C%7D%3D45%2F9%20%3D%205%24" />.