Can someone help me solve this math problem?

The correct answer is f(6) = 14.

f(x) is essentially the y-value, and the question is asking you:

if the value of x is 6, its corresponding y-value (or f(x)) is 14.

The answer is c because you turn 17.5% into a decimal which gives you .175 then you times that by $361.35 which gives you 63.23625 but then you round that which gives you 63.24. then you at 63.24 pulse 361.35 and you round it which gives you $425