Answer:
The answer to your question is: BC = 9
Step-by-step explanation:
Data
BC = 8x + 1
AB = 11
AC = 20x
AB + BC = AC
11 + 8x + 1 = 20x
12 + 8x = 20x
12 = 20x - 8x
12 = 12x
x = 12/12 = 1
BC = 8(1) + 1
BC = 8 + 1 = 9
AC = 20(1) = 20
11 + 9 = 20
