how do you tell the diffrence between a varigated tree and one that has deficiencies?

Well, once you have seen a variegated citrus you cannot make a mistake any more.
Look on the forum, there are many pictures.

The leaves in your Meyer lemon pic showing the deficiency symptoms have a very regular pattern of dark green/ light green, also all the leaves are virtually identical in their patterning.
Variegated patterning is related to the presence and / or abscence of green chlorophyll pigment from leaf areas, and tends to be more random from leaf to leaf, ranging from white ( chlorophyll absent ) to dark green ( normal ).
Some variegated varieties do have fairly regular patterns of variegation, such as green centre with white leaf margin.
The patterning due to nutrient deficiency is usually seen in either only the older leaves, or only the new growth, depending on which element is deficient.

thank you for the help