Question

The table shows the outputs y for different inputs x:

Input. (x)3 7 11 15.
Output. (y)4 6 8 10
Answer the following:
Part A: Do the data in this table represent a function? Justify your answer.
Part B: Compare the data in the table with the relation f(x) = 5x – 21. Which relation has a greater value when x = 11?
Part C: Using the relation in Part B, what is the value of x if f(x) = 99?

Answer 1

Part A : Yes the data in this table represent a function and that is because the value of "x" keeps changing.

Part B : 
f(x) = 5x – 21
f(11) = 5(11) - 21
        = 55 - 21
        = 34

Part C:
f(x) = 5x – 21
99 = 5x - 21
5x = 99 + 21
5x = 120
x = 24

I hope that the procedure is clear for you to understand and this is the answer that you were looking for.