Question

How do you identify equations as exponential growth, exponential decay, linear growth or linear decay `y=2x`?

Answer 1

`y=2x` represents linear growth

Explanation:

`y=2x` is a linear equation whereby `y` grows by 2 units for each unit increase of `x`. Hence, `y=2x` represents linear growth.

Similarly, `y=-2x` represents an example of linear decay.

Concerning exponential growth/decay::

`y =2^x` represents an example of exponential growth. - See below
graph{2^x [-10, 10, -5, 5]}

`y=2^-x` represents an example of exponential decay.. - See below
graph{2^-x [-10, 10, -5, 5]}