Q -------------R------------S
suppose this is your line,
R is the mid point
and it's given that
QR = 2x
and
RS = x+3
as R is the mid point of QS
so,
QR = RS
then,
2x = x + 3
2x - x =3
x = 3
as,
it's given that RS = x + 3
then,
RS = 3 + 3
= 6 units.
If you do the long division you'll see that it is x - 2.
I believe you just multiply the two numbers together and get 2.665