Answer:
They are the same. If you were to graph them, they would overlap.
Explanation:
Look at it this way:

Insert this value:

Now solve. Insert y:

Switch x and y:

Add 4 to both sides:

Use the rule
:

Multiply both sides by 2:

Divide both sides by 3:

Take the square root of both sides*:

Therefore:

This is not a function (by the way) because ±
means that there are two y values per x value. If you were to graph this, it would fail the vertical line test, which proves that it is not a function.
:Done
*You need to have the ± symbol when you take a square root because, although 2×2=4, (-2)×(-2)=4 as well. The square root of 4 could be either -2 or positive 2. The same can be said for the above result.