If 
and 
, find 
.
Given that 
and 
, we have to find |AB|
Then, 
and 
|A|=1×-1-2×3
=-7 (Expanding along R1)
|B|=1×(-2)-(-4)×3
=10 (Expanding along R1)
Since |AB|=|A||B|,
Therefore |AB|=-7×10=-70
1
If and , find .
Given that and , we have to find |AB|
Then, and
|A|=1×-1-2×3
=-7 (Expanding along R1)
|B|=1×(-2)-(-4)×3
=10 (Expanding along R1)
Since |AB|=|A||B|,
Therefore |AB|=-7×10=-70