Question

Resolva a equações:
|× 3 2 |
|5 2 1 | =12
|1 3 1|​

Answer 1

|× 3 2 |

|5 2 1 | =12

|1 3 1|

x.2.1+5.3.2+1.1.3 - 2.2.1-1.3.x-1.5.3=12

2x+30+3 -4-3x-15=12

-x +33 -19=12

-x +14=12

-x = -2

x = 2