Proportional/Non-proportional Relationships

Slope Formula

(y₂- y₁) / (x₂- x₁)

Unit Rate

A rate in which the second quantity is the comparison is one unit. Unite rates are often expressed using the word per, which means "for every one"

Rate

A ratio of two quantities measured in different units.

Rate of change

A ratio that compares the amount of change in a dependent variable to the amount of change in an independent variable. Also called SLOPE.

Proportional Relationship

A relationship between two quantities in which the ratio of one quantity to the other quantity is constant The graph is linear and always goes through (0,0).

Linear

A relationship or function that can be represented by a straight line.

Constant

A value that does not change

Proportion

An equation stating that two ratios are equal

Linear Relationship

Graphs of these relationships are always STRAIGHT LINES and in the form of y = mx + b.

Constant of Proportionality

In a proportional relationship, the constant value of the ratio of two proportional. You divide y by x to get it.

Nonportional Relationship

The graph of a non-proportional linear relationship is a straight line that does not pass through the origin.

Origin

The point where the x-axis and the y-axis intersect on the coordinate plane; (0,0).

Slope

The steepness of a line on a graph. Rise/run (change in y values / change in x values)

y intercept

The y coordinate of the point where a graph crosses the y axis.