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Chapter 7 Graphing Linear Equations Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-1 Chapter Sections 7.1 – The Cartesian Coordinate System and Linear Equations in Two Variables 7.2 – Graphing Linear Equations 7.3 – Slope of a Line 7.4 – Slope-Intercept and Point-Slope Forms of a Linear Equation 7.5 – Graphing Linear Inequalities 7.6 – Functions Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-2 2 Slope-Intercept and Point-Slope Forms of a Linear Equation Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-3 3 Slope-Intercept Form In the slope-intercept form, the graph of a linear equation will always be a straight line in the form y = mx + b were m is the slope of The line and b is the y-intercept (0, b). slope y-intercept y = mx + b Examples: 1 3 y = x+ y = 4x – 4 2 2 slope is 4 y-intercept is (0, -6) slope is 1 y-intercept is 3 2 (0, ) 2 Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-4 4 Slope-Intercept Form Write the equation -3x + 4y = 8 in slope-intercept form. Solve for y. 4y = 3x + 8 3x 8 y 4 3 8 y x 4 4 3 y x2 4 slope is y-intercept is (0, 2) Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-5 5 Point-Slope Form When the slope and a point on the line are known, we can use the point-slope form to determine the line. y y1 m( x x1 ) where m is the slope of the line and (x1, y1) is a point. Example: point (1, 3) and slope = 2: y 3 2( x 1) y 3 2x 2 y 2x 1 Copyright © 2015, 2011, 2007 Pearson Education, Inc. Chapter 7-6 6