Question

I need help with both 9 and 10

Answer 1

I'll answer problem 9 to get you started

Answer: Choice (2) 3x-1 = 2x+3

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Explanation:

We will plug x = 7 into each equation or inequality given to us. Then we determine if we get a true statement or not.

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Let's start with choice (1)

x + 3 > 6

7 + 3 > 6 .... x is replaced with 7

10 > 6

Since 10 is larger than 6, this makes the last inequality true. Therefore, the first inequality is true when x = 7. So we can rule out choice (1) since we are looking for a false statement.

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Move onto choice (2)

3x-1 = 2x+3

3*7-1 = 2*7+3 ... replace every x with 7

21-1 = 14+3

20 = 17

This is false since we don't get the same number on each side. Therefore, choice (2) is the final answer.

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Since we found the answer, we can stop here. But let's keep going to check the others.

choice (3)

2(x+1) = x+9

2*(7+1) = 7+9 ... plug in x = 7

2*(8) = 16

16 = 16

We get the same thing on both sides, so the equation is true. We can rule out choice (3).

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Now onto choice (4)

$-2x + 10 \le 0\\\\-2*7 + 10 \le 0\\\\-14 + 10 \le 0\\\\-4 \le 0$

This is true since -4 is to the left of 0 on the number line, which makes -4 smaller than 0. We can rule out choice (4).