Write an example of a linear function and one example of a nonlinear function. use x and y as variables.

Step-by-step explanation:

Example of a linear function:  y = -5x + 2.  Note that both x and y are to the first power:  y^1 and x^1.

Example of a nonlinear function:  y = 2x^2 - x - 13.  Here x is to the second power (which automatically makes this a nonlinear function).