Explain how a long-term environmental change can lead to the development of a new species.

like climate change, can permanently alter an ecosystem, but over time the change may cause some  

[Genetic variations] to become more favorable or less favorable in the new environment. If adaptations to the new environment are not present or do not develop, populations can become [extinct.]

When a long-term environmental change occurs, certain individuals in a population will be better adapted for the new environment than others. These individuals will be more likely to survive and pass on their traits to their offspring. Over many generations, these favorable adaptations build up in a population. This may lead to speciation, which is the development of a new species.

the answer to your question is a plant

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.

: -)