What is the distance of the image to this lense

[xinlan]

Homework Statement

A lens placed at the origin with its axis pointing along the x-axis produces a real inverted image at x = -24 cm that is twice as tall as the object

What is the image distance?

Homework Equations

m = -d'/d

The Attempt at a Solution

I thought d=24 cm. and h' = -2h
then use m = h'/h to solve for the m. which I got m = -2.
then I used m = -d'/d
-2 = -d'/24
d' = 48 cm.

I don't know where I did wrong..
please help me..
thanks..

 

[xinlan]

Never mind..
I got it.. :)

 

[vachan]

what did you get wrong>>