What are viruses considered to be non-living?

Viruses are often considered non-living because outside of a living cell, they do not exhibit the characteristics of living organisms: they are basically like crystals. But within a living organism, they become activated and are able to carry out life's activities like replication (a form of reproduction).

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides