The slope of a line, often denoted by the letter m, is defined as the ratio of the vertical change (rise) to the horizontal ...

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.

Predicting Values: Once you have a linear equation that represents a relationship, you can use it to predict values. For ...