36m5n5 ÷ (12m3)
If I had to guess, I'd say the 5's and 3's are exponents? Working under this assumption:
A property of exponents is the following:
am ÷ an = a(m-n)
Note that this is the inverse operation when multiplying like bases with exponents:
am x an = a(m+n)
This can be illustrated if we expand the factors with exponents in this way,
You can see that the three m's on the denominator can be cancelled with three on the numerator, leaving m2 on the numerator, proving that the property m(5-3) = m2.
You can treat the coefficients separately, so that the ratio 36/12 is reduced to 3. The n3 factor is just along for the ride since it cannot be simplified further.
So putting it all together we get: