Answer:
2.5
Step-by-step explanation:
1. intersecting chord theorem
2. Let where CB and DA intersect be X
3. CX * XB = DX * XA
4. 7*x = (x+1) * 2x
5. 7x = 2x^2 + 2x
6. 2x^2 - 5x = 0
7. x = 2.5 or 0
8. length cant be 0 so x = 2.5
