Question

The table below shows the squares of different numbers:

Answer 1

The table in Part A represents y as a function of x. This means that the value of Y is dependent on the value of X. The table can be represented by an equation that describes the relation of X and Y:
$y = x^{2}$ or $f(x) = x^{2}$
By substituting any value of X, you get a specific value of Y based from the given relationship, thus Y is a function of X. 

For Part B, the value of f(150) is $470 and it represents the total cost for borrowing a rowboat for 150 hours. By substituting the value of x = 150 into the function, you get the total cost:
$f(x) = 20 + 3x \\ where \\ x = 150 \\ f(150) = 20 + 3(150) \\ f(150) =20 + 450 \\ f(150) = 470$