Lesson 8: Graphing Multi-Variable Equations

Standard and Objectives A.CED.2 Create equations in two or more variables to represent relationships between quantities; graph equations on coordinate axes with labels and scales. SWBAT graph multi-variable equations from an equation in slope-intercept form SWBAT graph multi-variable equations from equations not in slope-intercept form SWBAT graph a multi-variable equation from a table

Vocabulary Y-intercept (b) – Shows where you _____________________. Also where the graph crosses the _________________. Represents the _________________. Slope (m) – Shows how you _________________________. Represents the _____________________. START Y-AXIS CONSTANT MOVE COEFFICIENT/SLOPE

Quick Check! Determine the slope and y-intercept for each of the following linear equations. y = 2/3x + 1 y = 5x – 2 y = -4x – 6 y = 1/4x – 7

Graphing a Linear Equation Y-INTERCEPT 1. Plot the _________________ 2. Use the _______________ to plot the second point. Move up (+) or down (–) the number of spaces of the rise Move right (+) or left (–) the number of spaces of the run SLOPE

Example 1 Given the equation y = 2/3x + 1, determine the slope and y-intercept and then graph the equation.

Example 2 Graph the Linear Equation from the table on your calculator Graph y = 3x – 2

Example 3 Re-write an equation in slope-intercept form and then graph the equation. Graph 2x + 4y = 12

Example 4 Determine which equation fits the values in the table A) y = x + 3 B) y = 2x – 5 C) y = 4x – 2 D) y = 5x + 3 X -5 -2 2 4 Y -22 -10 6 14

Example 5 Determine which equation fits the values in the table A) y = -2x B) y = 2x – 12 C) y = 3x + 3 D) y = -x + 3 X -3 -1 3 6 Y 4