I. Proportional Relationships:

        Directly Proportional: y = k x , where k is a constant

        Inversely Proportional: y = 

        Proportional to the power of x: y = k xⁿ, where n > 0 or y = k / xⁿ, where n > 0 and xⁿ

II. Rate of Change: Slope

        Using any two points on the line: point 1: (x₀, y₀) and (x_1, y₁)

III Formulas for Linear Function:

        y = b + mx , where b and m are constant, m is the slope and b is the vertical or y- intercept. The value of y when x = 0.
                                    This form of the linear function      is called the slope-intercept form.

        y - y₀ = m (x - x₀) is another form of the equation for a linear function when the slope m and a point is know on the line.
                                    This form is called the point-slope form.