PLEAAASE HELP ILL MARK BRAINLIEST

The answer is 69

Step-by-step explanation:

You have to substitute y by 9 and by 3

Step-by-step explanation:

Since y is equal to 9 and z is equal to 3, we do 10 x 9 - 7 x 3. 10 times 9 is 90, and 7 times 3 is 21.

Then, we do 90-21. 90-21=69. Therefore, 10y-7z = 69.

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.