Resposta:
Explicação passo a passo:
[tex]7)[/tex]
[tex]3A=3 \times\:\left(\begin{array}{ccc}1&-1&2\\0&3&4\\\end{array}\right) =\:\left(\begin{array}{ccc}3&-3&6\\0&9&12\\\end{array}\right)[/tex]
[tex]4B=4 \times\:\left(\begin{array}{ccc}4&0&-3\\-1&-2&3\\\end{array}\right) =\:\left(\begin{array}{ccc}16&0&-12\\-4&-8&12\\\end{array}\right)[/tex]
[tex]Portanto...[/tex]
[tex]3A+4B=[/tex]
[tex]\:\left(\begin{array}{ccc}3&-3&6\\0&9&12\\\end{array}\right)+\:\left(\begin{array}{ccc}16&0&-12\\-4&-8&12\\\end{array}\right)=\left(\begin{array}{ccc}19&-3&-6\\-4&1&24\\\end{array}\right)[/tex]
[tex]Resposta:(B)[/tex]
[tex]8)[/tex]
[tex]\left|\begin{array}{ccc}2&3\\4&8\\\end{array}\right|=2 \times8-3 \times4=16-12=4[/tex]
[tex]Resposta:(d)[/tex]
[tex]Feliz\;Ano\;Novo![/tex]
