Question 167477
12m^8y^6
---------
-9my^4 
.
First look at the coefficients (12/-9).  This can be reduced by dividing numerator and denominator by 3:
4m^8y^6
---------
-3my^4 
.
Now, look at the 'm's -- m^8= mmmmmmmm (eight m's on the top) and one 'm' on the bottom (denominator).  You cancel ONE of the m's leaving:
4m^7y^6
---------
-3y^4
.
Finally looking at the 'y's -- 6 y's on the numerator and 4 y's on the denominator -- you can cancel four y's from top and bottom:
4m^7y^2
---------
  -3
.
That's it. You cannot reduce any further.