Question

What is the rate of change and initial value for the linear relation that includes the points shown in the table?

x y
1 20
3 10
5 0
7 −10

Answer 1

First of all:  Note that this is a linear relationship.  If you start at any x and increase x by 2, by how much does y decrease?  Verify that this decrease is the same for any two adjacent x-values.  Can you figure out the slope of this straight line by doing that?  Now think about the y-value you'd get if you were to decrease x not by 2, but by 1.