which expression simplifies to 3x + 4z + 6?

The answer to your question is: x = -2 + -1.333333333z

It's a long explanation, so I only gave you the answer. If you need the explanation n all, just let me know ok :)

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.