Question

If y − 3 = 3x, which of the following sets represents possible inputs and outputs of the function, represented as ordered pairs?

(0, 3), (1, 6), (2, 9)}
{(3, 0), (6, 1), (9, 2)}
{(1, 3), (2, 6), (3, 9)}
{(3, 1), (6, 2), (9, 3)}

Answer 1

(0,3);(1,6);(2,9) using trial and error method

Answer 2

The set that represents possible inputs and outputs of the function is the first one, i.e. {(0, 3), (1, 6), (2, 9)}

Explanation:

In an ordered pair of numbers (wich represents points in a plane, lets say of axis x and y), we use the convention that the pair is represented by the values (x, y).

Taking this into account, we get one ordered pair, and put the value of x (input) in the equation, then clear the value of y (output) and match it with the second value in the ordered pair. If this pair is correct, we continue with the next pair of the set.

With this procedure, it is trivial that the correct answer is the first set of ordered pairs {(0, 3), (1, 6), (2, 9)}.