Bisections means the division of something in two equal halves.
Any point that cuts the line in its midpoint can be considered a bisector.
If point M stands in the midpoint of line RS, then it is its bisector and following the definition, it divides it in two equal segments
RM=MS.
> the bisector of RS is M
Now since we know that
RS=RM+MS,
RM=MS
and that MS=22
You can calculate the length of RS
RS=RM+MS=22+22=44
>RS=44