I read about linear growth and exponential growth and have something vague
if linear growth is defined as $y=1+x$ or $y=a+x$ where $a$ is the thing to grow and $x$ is the change in the thing
and if exponential growth is defined as $y=ab^z$ where $a$ will be the thing to grow and $b^z$ will be change in the unit of growth $b^0$ where $b$ represents the mechanism of growth and $z$ represents the number of times of growth
and if $y$ are the same representing the value of the thing after growth
how can we describe the growth represented by $y=a+x$ which is linear in the form $y=ab^z$ in which:
$1\rightarrow$ We will find relation between $x$ as the amount in change and the $b^z$ which is the amount of change in unit of growth
$2\rightarrow$ We will find that linear growth is an exponential growth which changes the mechanism of growth incrementally "$b$" and use it just one time "$z=1$"
I feel this relates to calculus and differentiation but I am confused
please help showing me the way to go to understand this or end my confusion
Thanks a lot.