Question

Encontre o valor de x.

$\left[\begin{array}{ccc}2&x&x\\1&2&1\\3&1&2\end{array}\right] =12$

Answer 1

Resposta:

x= -3/2

Explicação passo-a-passo:

2.2.2+3.x.1+1.1.x-3.2.x-1.x.2-1.1.2=12

8+3x+x-6x-2x-2=12

-4x+6=12

4x=6-12

4x= -6

x= -6/4

x=  -6÷2/4÷2

x= -3/2