New York State Learning Standards and Core Curriculum
NY-8.EE. Expressions, Equations and Inequalities
Understand the connections between proportional relationships, lines, and linear equations.
NY-8.EE.5. Graph proportional relationships, interpreting the unit rate as the slope of the graph. Compare two different proportional relationships represented in different ways.
NY-8.EE.6. Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y=mx for a line through the origin and the equations y=mx+b for a line intercepting the vertical axis at b.
Define, evaluate, and compare functions.
NY-8.F.3. Interpret the equation y = mx + b as defining a linear function, whose graph is a straight line. Recognize examples of functions that are linear and non-linear.