(adsbygoogle = window.adsbygoogle || []).push({}); Vectors question very shoooort :D

we have the vectors a ,b and c with the modules a=2,b=5 and c=7. If a+b+c=0 find a*b+b*c+a*c

Now,i tried a+b=-c and replace but i get nothing in the end..any ideas?

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# Homework Help: Vectors question very shoooort

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