In order to subtract two fractions, they need to have a common denominator which would be 12, so you need to change all the denominators to 12.
7/12 is still 7/12
1/6 is multiplied by 2/2 to become 2/12.
Then you can subtract.
7/12 - 2/12 = 5/12
So the simplest form would be 5/12
