Unit Rate/Direct Variation

proportional relationship

A linear relationship between 2 quantities in which one is a constant multiple of the other.

direct variation

A special type of linear relationship in which the ratio of any output value (y) to its corresponding input value (x) is proportional.

constant of proportionality (k)

The constant value of the ratio of two proportional quantities, general x and y, and written y=kx, where k is the factor of direct variation. (proportional coefficient of x).

y-intercept

The ordered pair where a line, curve, or surface intersect the y-axis and contains the x-coordinate of zero.

dependent quantity

The quantity that can take on different values only in response to its corresponding, independent quantity/variable.

independent quantity

The quantity that does not depend on another quantity or variable, but rather causes corresponding changes to the dependent quantity.

equivalent ratios

Two ratios that have the same value.

y=kx

direct variation formula