There is nothing wrong with the solution from the other tutor.
However, because of the way the software on this web site displays expressions with exponents, her work is hard to follow.
In addition, in practice the process of simplifying an expression like this is (for most students at least) is far easier if we look at the constants and each variable separately.
Here is what I would do with this....
-->
(1) Constants....
The constant is
(2) variable m....
The exponents are and
Add the exponents:
(3) variable n....
The exponents are and
Add the exponents:
Combine the three parts of the expression to get the final simplified expression:
Clarification of a point the student asked about....
In the factor "1/2", the 2 is in the denominator; so when all the parts are combined, the "2" is still in the denominator (and since the "1" of the fraction is in the numerator, we don't need to write it in the combined form of the answer).
I've added parentheses around the "2" in the denominator of the final form of the answer to try to help make this clear.
