Q12 of 256 Page 7

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


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