standard_description: Explain why the sum or product of two rational numbers is rational; that the sum of a rational number and an irrational number is irrational; and that the product of a nonzero rational number and an irrational number is irrational.
problem_activity: Sylvia bikes home along a straight road from her friend’s house, a distance of 8 miles. The graph shows her journey:
[IMG]
Describe what may have happened. Be sure to include details about her pace, points that indicate a change in action, and where she starts and stops.
Are all sections of the graph realistic? Explain your reasoning.


aligns: no