. Cho các ma trận: 2 4 6 7 1 2 1 34
, ,
3 5 7 0 4 3 2 6
ABC        
                

Hãy thực hiện các phép tính sau:
A B , A B 3 , 2
t t A B  ,
t AB , . ,
t AB
.
t A B C

The graph of the function f(x) = (x + 2)(x + 6) is shown below. which statement about the function is true? the function is positive for all real values of x where x > –4. the function is negative for all real values of x where –6 < x < –2. the function is positive for all real values of x where x < –6 or x > –3. the function is negative for all real values of x where x < –2.