Answer: x=3 and JM=9 units
Explanation:
Given:
in which BM is a perpendicular bisector of JK such that JB=BK and
.
Now in

JB=BK [given]
[right angle]
MB=MB [reflexive property]
[by SAS postulate of congruence]
⇒MJ=MK

Thus JM=

Hence, x=3 and JM=9 units