# Linear Functions : Input Variable x and Output Variable y

- Author:
- Lew W.S.

Assess yourself if you understood the concept of linear functions, where it involves two variables x and y.
For example y = x + 4 is a linear function.
We can also refer to y as a function of x, where y = x + 4.
The concept of x as a variable where input values are used to replace x,
and the concept of y as the variable that contain the output values calculated based on the "rule" or y = x + 4 is being reinforced in the practice here.
Fill in the correct corresponding values of y and x for the given values of x and y.