Identify an organism's need that is met by an abiotic factor A wolf's need for warmth, fur coat
A fish's need for food, water
A lizard's need for warmth, sun
A rabbit's need for food, grass

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.

: -)

a covalent bond, specfically triple bond