Answer: Choice G

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Reason:
The inequality for choice G solves to the following shown below.

In the second step, I divided both sides by 3 to undo the multiplication going on when saying "3x".
Once we arrive at
, the graph will have a closed endpoint at 7 and shading to the left. This is to visually describe all values of x that are 7 or smaller. The endpoint is included as part of the solution set.
This shows why choice G is the answer.
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Something like choice F has the inequality
solve to
after adding 2 to both sides. The graph of
involves a closed endpoint at 11 and shading to the left, which doesn't match the given number line graph. This allows us to rule out choice F.
Choices H and J are ruled out for similar reasoning.