Simple, what you're basically doing is simplifying,

well, you have 3x and you have

12/3=4
and you can "cancel" out an x, making your answer,

.
You may find it easiest if you convert all the fractions to decimal form:
5.433...
5.166...
5.756
Now reorder these from smallest to largest.
Note: I had to guess that by "68,90," you actually meant "68/90."
(5x-2y)(3x-2y)
Dont give me anything give it to the other lad down there