Question

ajuda 1) Dadás as matrizes A = [1/6 2/4] e b = [-2/3 5/4] A +B é igual a : a)[-1/9 5/8] b) [4/9 5/4] c)[4/9 7/4] d) [-1/9 7/8] 2) dadas as matrizes A =[1/6 2/4] e b [-2/3 5/4] A - B é igual a a) [3/3 -3/0 ] b)3/3 5/4] c)[ 4/9 -3/0] d) [-1/9 7/8] 3 ) dadas as matrizes A = [1/6 2/4] e b =[-2/3 5/4] A b e igual a a) [3/0 -3/46] b)[4/0 13/46] c)[4/9 13/0] d) [-1/0 13/8] 4) dadas as matrizes A = [2] B = [1/6 2/4] e c = [2/1/3 1/-1/1 3/5/-2] os determinantes das matrizes A b e C nesta ordem São a) 2 -8 e 23 b) 2,-7 e 23 c) 2 -8 e 22 d) 2 -5 e 25 por favor me ajude
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Answer 1

Explicação passo-a-passo:

assumindo que as matrizes são  :

A=$\left[\begin{array}{cc}1&2\\6&4\end{array}\right]$

b=$\left[\begin{array}{cc}-2&5\\3&4\end{array}\right]$

$A+B = \left[\begin{array}{cc}1-2&2+5\\6+3&4+4\end{array}\right]=\left[\begin{array}{cc}-1&7\\9&8\end{array}\right]$ letra d

2) dadas as matrizes A =[1/6 2/4] e b [-2/3 5/4]

A-B = $A-B = \left[\begin{array}{cc}1+2&2-5\\6-3&4-4\end{array}\right]=\left[\begin{array}{cc}3&-3\\3&0\end{array}\right]$ letra a)

3 ) dadas as matrizes A = [1/6 2/4] e b =[-2/3 5/4] A b

A*B=$\left[\begin{array}{cc}1*-2+2*3&1*5 + 2*4\\ 6*-2 +4*3 &6*5 +4*4 \end{array}\right]=\left[\begin{array}{cc}4&13\\ 0 &46 \end{array}\right]$

4) dadas as matrizes A = [2] B = [1/6 2/4] e c = [2/1/3 1/-1/1 3/5/-2] os determinantes das matrizes A b e C nesta ordem São

det(A)=2

multiplicando a diagonal principal e subtraindo a secundaria da matriz 2x2

1*4 - 2*6

4-12=-8

$\left[\begin{array}{ccc}2&1&3\\1&-1&5\\3&1&2\end{array}\right] \left[\begin{array}{cc}2&1\\1&-1\\3&1\end{array}\right]$

(2*-1*2) + (1*5*3)+(3*1*1) - ((1*1*2)+(2*5*1)+(3*-1*3))

-4+15+3 - (2+10-9)

14 - 3=11

bom fica entre a a) e a c) e provavelmente tem algum erro no enunciado da matriz c