Learning Targets:
• Write ratios of variable expressions.
• Write a rational function based on a real-world scenario.
SUGGESTED LEARNING STRATEGIES: Marking the Text, Close
Reading, Graphic Organizer, Create Representations, Guess and Check,
Simplify the Problem
Miguel and Cera have a son named Cory. Miguel teaches mathematics at
Sci-fi High School, and he enjoys making up problems for his algebra
students. Miguel used the following problem as a classroom warm-up
exercise.
As of today, Miguel’s age is five times Cory’s age. Cera’s age is three more than
four times Cory’s age.
Next year, Miguel’s age will be 10 more than three times Cory’s age then. As of
today, how many times as old as Cory is Cera?
1. If y is used to represent Cory’s current age in years, complete the
following table by filling in the appropriate expressions in terms of the
variable y.

Current Age (years) Age 1 Year From Now (years)
Cory y
Cera
Miguel
2. Write an equation in terms of y that could be used to solve Miguel’s
warm-up problem; then solve the problem using your equation.

3. Miguel’s original problem asked “How many times as old as Cory is
Cera?” He also could have asked “How much older is Cera than her son
Cory?” Explain the difference in meaning between these two questions.