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Equation of a Straight Line

8.F.A.3
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Aligned To Common Core Standard:

Grade 8 Functions - 8.F.A.3

What is the Equation of a Straight Line? The most discussed concept in mathematics is the concept of a straight line. If you were to ask the equation of a straight line, you would probably be confused because the term is vast and take various forms of equations depending on the facts you know about the line equation. Since the concept is broad, you can determine the equation of a straight line in the following various forms: y = m x + b; This is used when given the slope m and "y-intercept" b. (y- y1)/(x-x1) = m, this is used when we have the slope of the line, m, and one-point given such as P1 = (x1, y1) through which the line crosses. The above equation is written in a form that makes it clear that both the given point P1 and slope of the line calculated at any point (x, y) are the same. The relationship is further simplified as: y = m (x-x1) + y1 The above-written form is simpler and tidier but doesn't reveal the truth about how the equation was derived. Slope: m = (y2- y1)/ (x2-x1); as the line crosses two different points (x1, y1) and (x2, y2), find out the slope of the line first to proceed. These worksheets and lessons help students understand how to determine the equation of a line from given points that exist on the line.

Printable Worksheets And Lessons






Homework Sheets

I would be very surprised if students have a hard time with this after they complete all the homework sheets.

  • Homework 1 - Determine if the function is linear or non-linear.
  • Homework 2 - Linear- The equation must fit into the form y = mx + b The variables cannot have exponents. When graphed they must form a straight line.
  • Homework 3 - The range of change is constant so the graph shows a straight line. Straight Lines = linear equations.



Practice Worksheets

There is a ton of graphing in your future, if plan to tackle these problems.

  • Practice 1 - Use the table to determine if the equation is linear or nonlinear.
  • Practice 2 - Non-linear - Equations that do not graph as a straight line.
  • Practice 3 - More work with data tables.



Math Skill Quizzes

I put two different sub-skills together with every sheet.

  • Quiz 1 - Graphs and plotted points that help form a line image.
  • Quiz 2 - Which function is linear?
  • Quiz 3 - Plotted points with data tables.