What is the measure, in units, of CD?
A.17
B.12
C. 9
D. 2

Answer:
A.17
Step-by-step explanation:
x+3 + x+3 + 2x-1 + 2x-1 = x-7 + 3x+1 + 4x-8
x = 9
line CD = 2x-1
2(9) - 1
18 - 1
line CD = 17