Question

Encontre a matriz inversa.
B=[-5 8]
[0 4]

C=[-3 10]
[ 4 12]

D=[-4 3]
[0 8]

Answer 1

Se det = 0 , não existe inversa, para qualquer matriz

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Para matriz 2x2  (só para esta matrizes)

A=

a   b

c   d

A-¹=  (1/det A)  *   d   -b

                             -c   a

#####################################

B=

[-5 8]
[0 4]     ..det =-20-0 =-20   ≠0

B-¹=

(-1/20) * [4   -8]

              [0  -5]

--------------------------------------------------------------------

C=

[-3 10]
[ 4 12]   ...det C = -36-40 =-76

C-¹=

(-1/76)  * [12  -10]

              [-4     -3]

--------------------------------------------------

D=

[-4 3]
[0 8]   ...det D = -32-0 =-32

D-¹=

(-1/32) * [8   -3]

              [0   -4]