ANSWER
Perpendicular bisector
<u>EXPLANATION</u>
The perpendicular bisector of a line divides the line into two equal parts.
It forms a locus of points that are equidistant from the two given points.
Therefore the set of all points that are equidistant from two given points in a plane is the perpendicular bisector of the line joining the two points.
Please provide more information. This question is not able to be answered with the information provided. Try giving the full problem!
First for 7 we need to find out how many ninths are in a third and there are 3/9 in a third so now we multiply 3/9 by 2 which is 6/9 now we subtract 7/9-6/9 which is 1/9 so 1/9 is left. (Iff I'm wrong sorry I did this is like a minute.)