Ecosystems can stay stable for hundreds of years, but loss of resources or addition of disease can quickly change the dynamics of said ecosystem. True
OFalse

answer; /// i do believe its (heredity); good luck

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.

: -)