Problem 2.3 Comparing Costs

Today we learned about the y-intercept. Here are some useful definitions:

y-intercept: the point where the line crosses the y-axis on a graph or when x=0 in a table (the starting point)

coefficient: the rate of change AND/OR the number that multiplies a variable in an equation

In the equation y=mx+b, y=the dependant variable, m=the coefficient and/or rate of change, x= the independent variable, and b=the y-intercept.

Here's another example, using the problem with Emile and Henri that we did yesterday in class.

Henri's equation: d=1t+45
The coefficient of t is 1 and the y-intercept is 45

Emile's equation: d=2.5t
The coefficient of t is 2.5 and the y-intercept is 0.

If no y-intercept is stated in the equation (that means there is no addition), it is assumed to be 0.