AC = 16, AB = x + 1, and BC = x + 7. What is the measure of the length of AB? HELP

Answer:
5
Step-by-step explanation:
AC=AB+BC
so 16=x+1+x+7
which simplifies to 16=2x+8
subtract eight from both sides to get 8=2x
then divide by 2 to get that x=4
AB=x+1, which substitutes into 4+1=5