di ketahui matriks a= [2x 8 3 x] dan b= [x-3 -1 5x...

Question

di ketahui matriks a= [2x 8 3 x] dan b= [x-3 -1 5x x] jika |a|=|b|, tentukan nilai X

MT.Hario · Answer

Jawaban:
x = 6 atau x = -4

Penjelasan:
A = [2x 8 3 x] 
B = [x-3 -1 5x x]
det (A) = det (B)
2x(x) - 8(3) = (x - 3)(x) - (-1)(5x)
2x² - 24 = x² - 3x + 5x
2x² - x² - 2x - 24 = 0
x² - 2x - 24 = 0
(x - 6)(x + 4) = 0
diperoleh x = 6 atau x = -4

M. K · Answer

itu x² -2x -24 = 0 kok bisa jadi (x -6)(x+4) = 0, tolong bantu kak gak paham soalnya