Grade 8 Math: Linear Equations in Two Variables


This topic covers linear equations in two variables. This series of six lessons introduces the student to linear equations in two variables. First it introduces equations as prescriptions and then the topic begins to cover making tables from equations, and graphing equations. Finally, the student learns about the slope of a graph.

This introductory topic to linear equations in two variables sets the stage for working in multivariable equations.


Equations as Prescriptions

This lesson teaches students the basics of linear equations in two variables. It involves giving a linear equation in two variables and then assuming one variable is fixed to some number. The student is then taught how to solve for the other number using techniques they learned from linear equations in one variable.


Making Tables from Equations

This lesson continues the idea of treating an equation as a prescription to construct a table of values for a linear equation in two variables.


Linear Equations: Drawing Graphs from Tables

In this lesson, the student learns how to draw a graph on the coordinate grid given a table of values.


Linear Equations: Drawing Graphs by Making Tables

This lesson utilizes the previous two lessons in order to teach students how to draw a graph of a linear equation in two variables by first constructing a table and then drawing a graph based upon the table.


Linear Equations: Finding Slope from Graphs

In this lesson, the student learns the definition of slope. They see that for any given line, the slope can be found by finding the vertical change and dividing it by the horizontal change. The student also sees that the slope is the same for a line independent of the points selected. The student also learns the difference between positive and negative slope.


Linear Equations: Slope from Two Points

In this lesson, the student learns to find the slope given two points that constitute a line.



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