Answer :
AB + BC = AC
(x + 5) + (x +11) = 16
2x + 16 = 16
2x = 0
x = 0
thus:
AB = x + 5 = 0 + 5 = 5
BC = x + 11= 0 + 11 = 11
(x + 5) + (x +11) = 16
2x + 16 = 16
2x = 0
x = 0
thus:
AB = x + 5 = 0 + 5 = 5
BC = x + 11= 0 + 11 = 11