a direct variation is a relationship between two variables that can be expressed by an equation in which one variable is equal to a constant times the other. For instance,
[tex]y=mx[/tex]
in which variables x and y are related by a constant m. A numerical examples of a Direct variations are:
[tex]\begin{gathered} y=-5x \\ y=\frac{2}{3}x \\ y=-\frac{7}{6}x \end{gathered}[/tex]
etc. In our case, the figure shows a line. The general equation of a line is in the form
[tex]y=mx+b[/tex]
This is almost the same a direc variation, however it has the y-intercept b. In our case, form the graph, we can see that
b=4. In other words, b is the point in which the lines cross y-axis.
Hence, our line doesnt represent a Direct variation since there is a y-intercept b=4.
