I need to know the number I think it’s nine but yk I need some clarification

The edges MN and ON are congruent, so the triangle is isosceles. In particular, this means angles M and O are congruent. Angle N is right, so it has measure 90º. The interior angles to any triangle sum to 180º, so

2 • 5xº + 90º = 180º

10xº = 90º

x = 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.  

the battle of gettysburg is considered the "high water mark" of the confederacy because it marked the greatest advance of the confederate forces against the union.