You are trying to decide which cell phone plan to purchase. plan a chargeres $40 for a new phone and $20 a month for usage. plan b provides the phone for free, but has a fee of $30 a month for usage.
use the substitution method to determine when the two plans will cost the same.

Hmmm, might be in the 1,000s or an exact number: 2,567

Step-by-step explanation:

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.  

step-by-step explanation:

the answer is 128