Answer:
For the given functions f(x) and g(x) 
Step-by-step explanation:
Here, the given function are:

Now, simplifying for (f-g)(x) = f(x) - g(x):


Doing operation on LIKE TERMS, we get
f(x) - g(x) = 
Hence, for the given functions f(x) and g(x) 
First factor (x square -36), the answer will be (x+6)(x-6).
Second, cancel the x .
6x/ (x+6)(x-6)
4x/(6)(-6)
4x/-36
To insert fraction values;
1) Click on "math" found under the alpha option
2) Use right arrow key to move to the tab "FRAC"
3) Select 1st option for fraction
4) Write out Fraction
Hope I helped :)