<span>The names of the three eras identified on the x-axis in model 1 answers are Paleozoic, Mesozoic and Cenozoic. It can be seen from the graph that a mass extinction happened 444 million years ago in Paleozoic era, another happened 254 million years ago at end of Paleozoic era and marked the beginning of Mesozoic era. The final mass extinction happened 65 million years ago at end of Mesozoic era in which dinosaurs went extinct.</span>
The country population would be 827 million in about 20 years.
This can be found by replacing "t" with 20 and solving. The solution would be about 8273.28 million. Thus meaning in about 20 years, the population would be 827 million.
Answer: (4, -9)
<u>Step-by-step explanation:</u>
Use elimination method. Manipulate one (or both) equations to eliminate one of the variables and solve for the remaining variable. <em>I will be eliminating y</em>
6x + y = 15 → 2(6x + y = 15) → 12x + 2y = 30
-7x - 2y = -10 → 1(-7x + 2y = -10) → <u> -7x - 2y = -10</u>
5x = 20
x = 4
Next, replace "x" with "4" into either equation and solve for y.
6(4) + y = 15
24 + y = 15
y = -9
<u>Check:</u>
Plug in x = 4 and y = -9 into the other equation to verify it makes a true statement.
-7x - 2y = -10
-7(4) - 2(-9) = -10
-28 - -18 = -10
-28 + 18 = -10
-10 = -10 
Ok so the first one is
1.x=135
2.x=-23
3.x=3
4.x=70
Answer: Choice B
{(0,0), (1,2), (2,4), (3,4)}
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Explanation:
A function is only possible if each x input leads to exactly one y output. For choice A, we have x = 1 lead to y = 3 and y = 5 at the same time, which is what the points (1,3) and (1,5) are saying. Therefore, choice A is not a function.
Choice C is also ruled out because x = 2 repeats itself as well. In this case, (2,3) and (2,4) means that the input x = 2 leads to the two outputs y = 3 and y = 4.
Choice D can be eliminated also for two reasons: x = 0 shows up twice, so does x = 2.
Only choice B has each x value listed one time only. So that means each input leads to exactly one output.
If you graph choice A, C or D, you'll find they fail the vertical line test. The vertical line test is where you test if you can draw a vertical line through more than one point on the graph. If you can draw a vertical line through more than one point on the graph, then the relation fails to be a function.
