Final answer:
To find f(339) and f(-129) for the function f(x) = x + 4, simply add 4 to each x value, giving f(339) = 343 and f(-129) = -125.
Step-by-step explanation:
The student has asked to find the values of the function f(x) = x + 4 when x is 339 and -129. The function simply adds 4 to any value of x that is input.
To find f(339), we add 4 to 339, which gives us 343. Similarly, to find f(-129), we add 4 to -129, giving us -125.
Therefore, the correct answers are:
f(339) = 339 + 4 = 343
f(-129) = -129 + 4 = -125