The fourth group of fractions are all equal to each other: 2/3 is equal to 6/9, if you create a common denominator you will see that they are equivalent. Also, if you created a common denominator of 18 for both, it would be true that it would come out as 12/18. 12/18 can also be reduced to either 6/9 or 2/3, but 2/3 is the most simplified version.
