8th Grade · Expressions & Equations
Proportional Relationship
8.EE.B.5
Definition
A relationship between two quantities with a constant ratio, written y equals k times x. Its graph is a straight line through the origin.
Teach it
Where it is taught, with guided notes, practice, homework, an exit ticket and an interactive Teacher Deck.
Examples
- 3/1 = 6/2 = 9/3 = 3, so y is always 3 × x.
- Test: does y divided by x give the same number every time?
Key rule
A proportional relationship's graph is always a straight line through the origin.
Memory hook
Same ratio every time, line through the origin.