Simplest form for 9/6

9/6 = 1 3/6
⇒ which equal 1 1/2

To find the simplest form, you must find the lowest common multiple.  9 and 6 are both divisible by 3.  9 / 3 = 3.  6 / 3 = 2.  This gives 3/2.  That could be the answer, or (if you have to give it as a mixed fraction) 1 1/2.