~ 2.8 ~

Comparing Relationships with Equations

Learning Targets

  • I can decide if a relationship represented by an equation is proportional or not.

Notes

If two quantities are in a proportional relationship, then their quotient is always the same. This table represents different values of a and b, two quantities that are in a proportional relationship.

Activities

8.2 More Conversions

The other day you worked with converting meters, centimeters, and millimeters. Here are some more unit conversions.

1. Use the equation below, where F represents degrees Fahrenheit and C represents degrees Celsius, to complete the table.

2. Use the equation c = 2.54n, where c represents the length in centimeters and n represents the length in inches, to complete the table.

3. Are these proportional relationships? Explain why or why not.

Add to Your Notes

Proportional Relationships are written in equations in the form:

y = kx

kx = y

8.3 Total Edge Length, Surface Area, and Volume

Here are some cubes with different side lengths. Complete each table. Be prepared to explain your reasoning.

  1. How long is the total edge length of each cube?

2. What is the surface area of each cube?

3. What is the volume of each cube?

4. Which of these relationships is proportional? Explain how you know.

5. Write equations for the total edge length E, total surface area A, and volume V of a cube with side length s.

Add to Your Notes

If a table represents a proportional relationship between x and y, then the unit rates y/x are always the same.


Summary

Assignment

Check Google Classroom!