Concave Mirror and objects distance

[sheri1987]

Homework Statement

A concave mirror (f = 44 cm) produces an image whose distance from the mirror is one-fourth the object distance.

(a) Determine the object distance.
cm

(b) Determine the (positive) image distance.
cm

Homework Equations

1/do +1/di =1/f do=object distance and di=image distance

The Attempt at a Solution

Since there are two unknowns I thought I could change the equation to 1/do + 1/4do = 1/f...and solve but this wasn't turning out right? am I going about this the wrong way?

 

[Snazzy]

Is 1/4do equal to (1/4)do or 1/(4do)? In any case, if the image distance is one-fourth the object distance, does that mean that di = 4do?