Look at the ray diagram below, move the mouse to move the object (red), see what happens to its image (transparent).
you can see there's a relationship between the object's its image's distances to the lens.
For the relationship between te object's and image's distance to the lens, we have the lens formula:
1/f=1/v-1/uIf you don't understand the technical terms in the formula, see Ray diagram, mirror formula and magnification formula
And for the relationship between object's height and its image's height, we have the magnification formula for lenses:
M=hi/ho=v/u