Tolong di jawab soal tentang determinan.... Question from @rezaandrian97

Takamori37 Dengan determinan A.
det A = (1)(1)(2) + (2)(4)(3) + (3)(2)(4) - [(3)(1)(3) + (4)(4)(1) + (2)(2)(2)]
det A = 2 + 24 + 24 - [9 + 16 + 8]
det A = 50 - 33
det A = 17

Dengan determinan B.
det B = (1)(1)(2) + (2)(k)(3) + (3)(2)(4) - [(3)(1)(3) + (4)(k)(1) + (2)(2)(2)]
det B = 2 + 6k + 24 - [9 + 4k + 8]
det B = 26 + 6k - 4k - 17
det B = 2k + 9

Dengan demikian:
det B = 2. det A
2k+9 = 2(17)
2k+9 = 34
2k = 34 - 9
2k = 25
k = 25/2

1 votes Thanks 1

izharulhaq78 $\displaystyle A=\left[\begin{array}{ccc}1&2&3\\2&1&4\\3&4&2\end{array}\right]\\|A|=\left[\begin{array}{ccc}1&2&3\\2&1&4\\3&4&2\end{array}\right]\left[\begin{array}{ccc}1&2\\2&1\\3&4\end{array}\right]\\|A|=1\cdot1\cdot2+2\cdot4\cdot3+3\cdot2\cdot4-3\cdot1\cdot3-4\cdot4\cdot1-2\cdot2\cdot2\\|A|=2+24+24-9-16-8\\|A|=24-7\\|A|=17\\\\|B|=2|A|\\|B|=2\times17\\|B|=34$

$\displaystyle |B|=\left[\begin{array}{ccc}1&2&3\\2&1&k\\3&4&2\end{array}\right]\left[\begin{array}{ccc}1&2\\2&1\\3&4\end{array}\right]\\34=1\cdot1\cdot2+2\cdot k\cdot3+3\cdot2\cdot4-3\cdot1\cdot3-4\cdot k\cdot1-2\cdot2\cdot2\\34=2+6k+24-9-4k-8\\34=6k+24-9-4k-6\\34=2k+24-15\\34=2k+9\\34-9=2k\\34-9=2k\\25=2k\\\boxed{\boxed{\frac{25}{2}\text{ atau }12,5=k}}}$

2 votes Thanks 2

Minta tolong jawab pr saya yang bagian 1 a dan c ,,kalo bisa bagian 2 juga terimakasih.

Kan 0,5 = 1/2 kalau 0,3 =? 0,1 =? 0,05 =? 0,25=?

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