Answer:
The answer to your question is x = 21
Step-by-step explanation:
Equation

- Multiply both sides by 7

- Simplify
2x = 42
- Divide both sides by 2

- Simplify
x = 21
For the first one just do the multiplication as you do normally.
For the second one, you have to put a zero behind before calculating the numbers in front
<h3>
Answer: Choice C</h3><h3>
{ (-2,2), (0,2), (7,2), (11,2) }</h3>
Here we don't have any repeated x values.
In choice A, x = 2 repeats. In other words, x = 2 leads to multiple y outputs. So this is not a function. Choices B and D are similar stories. A function is only possible if every x leads to exactly one y value only. The graph must pass the vertical line test.
Side note: the y values can repeat, but the function won't be one-to-one.