Question

dadas as matrizes A=(3 2 ) (2 1) e B=(0 1) (-3 4) marque a alternativa que contem o resultado de A¹ + B

Answer 1

A = $\left[\begin{array}{ccc}3&2\\2&1\end{array}\right] . \left[\begin{array}{ccc}a&b\\c&d\end{array}\right] = \left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

3a+2b=1      2a+b=0
3c+2d=0      2c+d=1

b=-2a                        b=-2a
3a+2.(-2a)=1            b=-2.-1
3a-4a=1                    b=-3
-a=1
a=-1

2c+d=1                 d=1-2c
d=1-2c                  d=1-2.1
3c+2d=0               d=1-2
2c+2.(1-2c)=0       d=-1
2c+2-4c=0
-2c=-2
c=1

Logo A¹: $\left[\begin{array}{ccc}-1&-3\\1&-1\end{array}\right]$

A¹+B = $\left[\begin{array}{ccc}-1&3\\1&-1\end{array}\right] + \left[\begin{array}{ccc}0&1\\-3&4\end{array}\right] = \left[\begin{array}{ccc}-1&4\\-2&3\end{array}\right]$

Espero ter ajudado!