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Answer: Choice C) 8 ∉ A; 8 ∈ B</h3>
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Explanation:
Let's check choice A
If we plugged x = 5 into the inequality for set A, then,
x+2 > 10
5+2 > 10
7 > 10
which is false. So 5 ∉ A is a true statement. It means "5 is not in set A".
Let's plug x = 5 into the inequality for set B
2x > 10
2*5 > 10
10 > 10
Which is false. So x = 5 is not in set B. The statement 5 ∈ B is false. It should be 5 ∉ B instead.
We can cross choice A off the list.
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Now onto choice B
Let's plug x = 6 into the inequality for set A
x+2 > 10
6+2 > 10
8 > 10
This is false, so saying 6 ∈ A is false.
Cross choice B off the list.
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Choice C
If we plugged x = 8 into the inequality for set A, then x+2 > 10 would turn into 10 > 10, but that's false. So saying 8 ∉ A is a true statement.
If we plugged x = 8 into the inequality for set B, then we'd go from 2x > 10 to 16 > 10. That being true leads to 8 ∈ B being true.
We conclude that choice C is the final answer since <u>both</u> 8 ∉ A and 8 ∈ B are true statements.
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We could stop at choice C, as we already found the answer, but let's check choice D.
Plug x = 9 into the inequality for set A
x+2 > 10
9+2 > 10
11 > 10
So saying 9 ∈ A is true, since x = 9 makes x+2 > 10 true.
Now try x = 9 into set B
2x > 10
2*9 > 10
18 > 10
We see that x = 9 is also in set B. So it should be 9 ∈ B and not 9 ∉ B
In other words, the first part of D is correct, but the second part is not.
We can cross choice D off the list.
