Question

A=-5i+6j-5k

B=7i+8j+4k

Find A×B

Answer 1

$${\bf A}×{\bf B}= (-5{\bf i}+6{\bf j}-5{\bf k})\times (7{\bf i}+8{\bf j}+4{\bf k})\\ =-40{\bf k}+20{\bf j}-42{\bf k}+24{\bf i}-35{\bf j}-40{\bf i}\\ =-16{\bf i}-15{\bf j}-82{\bf k}$$