As shown in the figure, a combination of a thin plano concave lens and a thin plano convex lens is used to image an object placed at infinity. The radius of curvature of both the lenses is $30 \mathrm{cm}$ and refraction index of the material for both the lenses is $1.75$. Both the lenses are placed at distance of $40 \mathrm{cm}$ from each other. Due to the combination, the image of the object is formed at distance $\mathrm{x}=\mathrm{\_\_\_\_\_\_\_cm}$ from plano concave lens.