Hello there!
The Distributive Property allows us to multiply any number/variable outside of the parenthesis by all inside numbers/variables within the parenthesis.
For example;
2(3 + 4)
"2" is our outside number.
"3" and "4" are our inside numbers.
Multiple our outside number by all inside numbers.
2(3) + 2(4)
6 + 8
14.
This is how the Distributive Property works.
Now, let's answer our questions doing this.
#1.)
7(3f + 6)
7(3f) + 7(6)
21f + 42 -- This is your simplified expression for (#1.)
#2.)
4(9 - 2f)
4(9) + 4(-2f)
36 - 8f -- This is your simplified expression for (#2.)
#3.)
5(8 - f)
5(8) + 5(f)
40 + 5f -- This is your simplified expression for (#3.)
I hope this helps!