Determine image distance relative to lens

1. The problem statement, all variables and given/known data
Two identical diverging lenses are separated by 13 cm. The focal length of each lens is -6.5 cm. An object is located 3.0 cm to the left of the lens that is on the left. Determine the final image distance relative to the lens on the right.

2. Relevant equations
1/i + 1/o = 1/f

1/i = 1/f - 1/o

3. The attempt at a solution
1/i = 1/-6.5 - 1/3
i= -.487

13 + .487 = 13.487 cm

I feel like I'm not doing this right at all.. can someone please let me know if I'm even on the right track?

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 Recognitions: Homework Help 13 + .487 = 13.487 cm This is the object distance for the second lens. Find the final image distance from the second lens.
 Ok so I took 1/13.487 + 1/i = 1/-6.5 and I solved for i and got -4.386 cm. Is this correct, or should I have used -13.487 and got -12.547 as my answer?

Recognitions:
Homework Help

Determine image distance relative to lens

and I solved for i and got -4.386 cm.
This is correct.

 It's telling me that answer is incorrect.. I guess I'll try the -12.547 next
 Recognitions: Homework Help 1/i = 1/-6.5 - 1/3 i= -.487 Check this calculation.