To graph an equation, first choose some x-values you like. Then, calculate the corresponding y-values using the equation. Now you have several number pairs (ordered pairs) that you can PLOT as POINTS (the x and y values are the x- and y-coordinates of the point).
In this lesson, the equations are LINEAR equations, so we can draw a line through the points to complete the graph. Of course, there also exist other types of equations whose graphs are not straight lines — you will learn about those in algebra I and algebra II courses.
Introduction to slope — video lesson
Variable on both sides — video lesson
Math Mammoth Grade 7 curriculum (pre-algebra)