Remember that
If two figures are similar, then the ratio of its corresponding sides is proportional
so
In this problem
we have that
JKLM is similar to NPQR
that means
JK/NP=KL/PQ=LM/QR=JM/NR
so
LM/QR=JM/NR
substitute given values
x/22=12/24
solve for x
x=(12/24)*22
x=11