High School · Creating Equations

CCSS.MATH.CONTENT.HSA.CED.A.2

Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales.

Read this standard on the official Common Core site

Lessons that teach this standard

• Parallel and Perpendicular Lines: The Slope Rules

  Parallel lines have equal slopes and perpendicular lines have negative reciprocal slopes — why both rules are true, and how to write equations using them.

• Point-Slope Form: Writing a Line from One Point

  Learn point-slope form, why it is the slope formula rearranged, and how to use it to write a line's equation from a single point and a slope.

• Standard Form of a Linear Equation: Ax + By = C

  What standard form is, when it beats slope-intercept form, how to convert between the two, and how to find the slope without rearranging.

• How to Write the Equation of a Line from Two Points

  Find a line's equation from any two points: compute the slope, substitute into point-slope form, then simplify — with worked examples and full solutions.

• x-Intercepts and y-Intercepts: Finding Where a Line Crosses

  Find the x- and y-intercepts of any equation by setting the other variable to zero, why that works, and what intercepts mean in a real situation.