Given:
CK = 3x + 23
KT = 5x + 7
If K is the midpoint of CT, then CK = KT. Then,

Finding x:
Subtracting 3x from both sides:

Subtracting 7 from both sides:

And dividing both sides by 2:

x = 8.
Finding CT:
K is the midpoint of CT, then CT = CK + KT

CT = 94.
Answer:
x = 8
CT = 94