A21 foot beam is to be cut into three pieces so that the second and the third piece are each 3 times the length of the first piece if x represents the length of the shorter piece, find the lengths of all three pieces

x+3x+3x=21

7x=21

x=3

3, 9, 9=21

the answers are 3, 9, and 9

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.