Question

determine o valor de x:


$a= \left[\begin{array}{ccc}3&x\\4&-1\\\end{array}\right] =9$


$b) \left[\begin{array}{ccc}2&x&x\\-1&-2&-1\\3&1&2\end{array}\right] =6$

Answer 1

Explicação passo-a-passo:

(3 x)

= 9

(4 -1)

3.(-1)- 4.(x)=9

-3-4x=9

-4x=9+3

-4x=12

x=12/-4

x=-3

(2 x x)

(-1 -2 -1) = 6

(3 1 2)

(2 x x)(2 x)

(-1 -2 -1)(-1 -2) =6

(3 1 2)(3 1)

-8-3x-x-(-6x-2-2x)=6

-4x-8-(-8x-2)=6

-4x+8x-8+2=6

4x-6=6

4x=6+6

4x=12

x=12/4

x=3