ok the question is:

consider a concave mirror with a focal length of 13.72 cm
find the image distance when the object distance is 6.86 cm.

ok so i did
1/6.86 + 1/q = 1/13.72
so 1/q = -.0728862974
is this right?

2 answers

Yes. Converting to the image distance, that means q = -13.9 cm
thanks :]