Answer:
f(x) = 3x + 2
Step-by-step explanation:
That's easy to find out. You have your input number, which is your x value, and you have your output number which is your y value (or f(x)).
All you have to do is see if each of the proposed answer works for ALL entries in the data set.
f(x) = 3x + 2
for x = 3 ===> 11 = 3 (3) + 2 = 11 YES
for x = 5 ===> 17 = 3 (5) + 2 = 17 YES
for x = 7 ===> 23 = 3 (7) + 2 = 23 YES
for x = 9 ===> 29 = 3 (9) + 2 = 29 YES
f(x) = 2x + 5
for x = 3 ===> 11 = 2 (3) + 5 = 11 YES
for x = 5 ===> 17 = 2 (5) + 5 = 15 NO - we stop here for this function
f(x) = x + 7
for x = 3 ===> 11 = (3) + 7 = 10 NO - we stop here for this function
f(x) = 3x + 1
for x = 3 ===> 11 = 3 (3) + 1 = 10 NO - we stop here for this function