Can a genius help me here. I know the answer is x = 23 cm, but how, i want to understand please.?

Two lenses are placed on the x-axis. The first lens is a diverging lens with focal length 4cm placed at x = -2cm. The second lens is a converging lens with focal length 7cm placed at x = 8cm. If an object is placed at x = -18cm, what is the position of the image on the x-axis? (Find the answer to the nearest centimeter).