The given expression is
[tex]f(n)=3n-7[/tex]
Now, we need to find f(5) - f(4). In other words, we need to find the value of the function when n=5 and n=4, then we subtract them.
Finding f(5)
[tex]f(5)=3(5)-7=15-7=8[/tex]
Finding f(4)
[tex]f(4)=3(4)-7=12-7=5[/tex]
Then, we subtract to get the answer
[tex]f(5)-f(4)=8-5=3[/tex]
Therefore, the answer is 3.
