Does anyone know how to me with the letters in math, i dont understand it, and i need , someone ? if you can can you tell me in step by step?

Step-by-step explanation:

Letters are variables and those variable can store a number

Ex: x=5  y=2

evaluate : 3x+2y

we know that x is 5, so we know that 3x would be 15

we know that y is 2, so we know that 2x would be 4

then it says to add 3x and 2y, we would add 15 and 4 to get 19

(This is a very simple example, when you get older, the expression would be much more confusing.

i used to know how to do this in 7th but i forget easily

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.