SOLUTION: if (xyz)^0 is equal to 1 then what is (x+y+z)^0?

It's equal to 1.

But the converse is not true.

 is meaningless.

Since you are given that (xyz)^0 = 1 then you are certain that 
none of x,y, and z are 0, because if one of them were, then 
(xyz)^0 would be meaningless, not 1.

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But suppose it had been this way instead:

if (x+y+z)^0 is equal to 1
then what is (xyz)^0 ?

Then if x and y were 1 and z were 0 then  would be  and
that would be 1.  But then  would be meaningless, not 1, for it would be


Edwin