Lesson 7.3: Slope-Point Form of a Linear Equation

Lesson 7.3 video link here. (Video under development)

The slope-intercept form of a linear equation is easy to interpret and is nice to work with when you know the slope and the y-intercept of the corresponding graph. When the only known point is not the y-intercept, the slope-intercept form is less convenient. A third way of representing a linear equation is to use the slope-point form. This form is useful when you know the slope and a point. Contextually, this form is particularly useful when a system's rate is known (the slope) along with the state of that system at some point (this known point is often not the y-intercept).

 


In Lesson 7.3, you will learn about

  • the slope-point form of a linear equation

 

Warm Up

Investigation

Line A has a slope of 2 and it passes through the point (6,4).

  1. State two other points that will be on line A.


  2. The information about line A can be represented using the slope formula as shown.



    One point at a time, substitute the coordinates of the points you determined in part 1 into the equation . What do you notice?

  3. A point on line A has an x-coordinate of 2.5. Use the equation to determine the y-coordinate of this point.


  4. Use your responses to the previous questions to explain how the slope formula can be used as a linear equation.