Question

Como se faz???

x=2 A -3B

Answer 1

A=(aij)3x3 e B=(bij)3x3

A=$\left[\begin{array}{ccc}a11&a12&a13\\a21&a22&a23\\a31&a32&a33\end{array}\right]$

Agora vamos usar a lei de formaçao para descobrir os elementos
aij=1+2j
a11=1+2.1=3
a12=1+2.2=5
a13=1+2.3=7
a21=1+2.1=3
a22=1+2.2=5
a23=1+2.3=7
a31=3
a32=5
a33=7

Nossa matriz fica da seguinte forma:
A=$\left[\begin{array}{ccc}3&5&7\\3&5&7\\3&5&7\end{array}\right]$

Agora com B

B=$\left[\begin{array}{ccc}b11&b12&b13\\b21&b22&b23\\b31&b32&b33\end{array}\right]$

bij=2i-j+1
b11=2.1-1+1=2
b12=2.1-2+1=1
b13=2.1-3+1=0
b21=2.2-1+1=4
b22=2.2-2+1=3
b23=2.2-3+1=2
b31=2.3-1+1=6
b32=2.3-2+1=5
b33=2.3-3+1=4

B=$\left[\begin{array}{ccc}2&1&0\\4&3&2\\6&5&4\end{array}\right]$

Como X=2A-3B
X=2.$\left[\begin{array}{ccc}3&5&7\\3&5&7\\3&5&7\end{array}\right]$ -
3.$\left[\begin{array}{ccc}2&1&0\\4&3&2\\6&5&4\end{array}\right]$

X=$\left[\begin{array}{ccc}6&10&14\\6&10&14\\6&10&14\end{array}\right]$- $\left[\begin{array}{ccc}6&3&0\\12&9&6\\18&15&12\end{array}\right]$

X=$\left[\begin{array}{ccc}0&7&14\\-6&1&8\\-12&-5&2\end{array}\right]$