Question

. What is a y-intercept. In a real life application what does it represent.

Answer 1

the y-intercept is when x = 0. it is just that, an incercept of the y-axis.
it's point is (0,b) where b is some point along the y-axis. 0 = x

this means that for any given equation, the y-intercept represents a "starting spot". for instance, if you are talking about time, then the y-intercept is the value when the time = 0.
or if you are talking about distance, then the y-intercept is the value when distance = 0.
etc. it's the initial value to any given equation.

Answer 2

flag fall in a phone call
you pay 20¢ connecting fee then a standard rate per time

Answer 3

similarly a taxi fare,
you pay 3$ to get in then you pay for each kilometer or whatever