if it's being reflected across the y-axis then that should go in to the negative side of the graph and the same if its being reflected across the x-axis, in which case it would be x,-y
The question is asking you to reflect over the y-axis. You pick a random point in the first quadrant and reflect that point over the y-axis. The point will land in the second quadrant and the x-value will have been negated (changed sign).
The ten thousand place is 1,000 times greater than the tens place. This is because every place value is ten times greater than the other place value before it.