We want to simplify the following expression
To simplify it, we must operate together everything that has the variable f and the rest together. The part that does not have the variable f is operated as follows
Now, we want to operate all other terms that are related to the variable f. To operate them, we simply operate the numbers that are right next to the variable. Once we operate them, we put the variable f next to it. So we get
Now, we put both parts together, so we have
