Answer: 24 (choice C)
Assuming M is a midpoint of KW, this means that WM and KM are congruent
WM = KM
x+3 = 2(x-3) ... substitution
x+3 = 2x-6
2x-6 = x+3
2x-6-x = x+3-x .... subtract x from both sides
x-6 = 3
x-6+6 = 3+6 ... add 6 to both sides
x = 9
Use x = 9 to find the length of WM
WM = x+3 = 9+3 = 12
Which can be used to find the length of KM as well
KM = 2(x-3) = 2(9-3) = 2(6) = 12
both lengths are the same (12) as expected
This makes WK to be
WK = WM + KM
WK = 12 + 12
WK = 24
