Question

Gabarito dessas duas ultimas questões?

Answer 1

7) Para a matriz ser simétrica:

4x-41 = -9 -> 4x = 32 -> x = 8

24 = z³-3 -> z³ = 27 -> z=3

y+4 = 3y-6 -> 10 = 2y -> y=5

8)

$\left[\begin{array}{ccc}x&1&2\\3&y&5\\2&3&z\end{array}\right] \left[\begin{array}{ccc}B1&0&0\\0&B2&0\\0&0&B3\end{array}\right]=\left[\begin{array}{ccc}2&3&10\\6&12&25\\4&9&20\end{array}\right] \\ \\ x*B1=2 \\ B2=3 \\ 2*B3=10 \\ 3*B1=6 \\ y*B2= 12 \\ 5*B3=25 \\ 2*B1 = 4 \\ 3*B2 = 9 \\ z*B3 = 20 \\ B3=5 \\ B2=3 \\ B1=2 \\ x*2=2 \: \:\:\:\:\: x=1 \\ y*3=12 \:\:\:\:\: y=4 \\ z*5=20 \:\:\:\:\: z=4$