If X is the midpoint of AB, then AX=BX by definition of a midpoint.
How to determine the justification of x
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x is the midpoint of ab
If X is the midpoint of AB, then AX=BX by definition of a midpoint.
The definition of a midpoint of a segment AB is that it is a point that divides AB into two segments with equal lengths.
So, since X is the midpoint of AB, it follows that AX=BX.