20 points i will mark brainiest Question 4

(08.03)

Solve the system of equations and choose the correct answer from the list of options.

x − y = 7

y = 3x + 12

Question 4 options:

1)

2 over 19 comma 2 over 33

2)

negative 2 over 19 comma negative 33 over 2

3)

negative 19 over 2 comma negative 33 over 2

4)

19 over 2 comma 33 over 2

x = -9 1/2

y = -16 1/2

Step-by-step explanation:

x - y = 7

solve the above for 'y':  -y = 7 - x

multiple each side by -1:  y = x - 7

now both equations are in 'y=' form

x - 7 = 3x + 12

-2x - 7 = 12

-2x = 19

x = -19/2 or -9 1/2

-9.5 - y = 7

-y = 16.5

y = -16.5 or -16 1/2

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.  

answer: 1 + 1 = 11

step-by-step explanation: