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ALGEBRA 1 CC Graphing and Writing Equations in SlopeIntercept Form • The three forms of writing a linear equation that we will cover this week • Slope-Intercept form • Standard Form • Point-Slope Form y mx b Ax By C y y1 m x x1 Example 1 • Write an equation of the line shown Example 2 • Write an equation of the line that passes through the points (4, -2) and (-2, 2) Example 3 • Write the equation of the line that passes through the point (-4, -9) and has a slope of 2. Graphing a Linear Equation • Step 1: Rewrite the equation in slope-intercept form (if necessary). • Step 2: Identify the slope and y-intercept • Step 3: Plot the y-intercept • Step 4: Use the slope to plot a second point and then draw a line through the two points. • It is optional, but highly recommended to draw more than two points to graph a linear equation Example 4 & 5 • Identify the slope and y-intercept of the line with the given equations and then graph the equations. 4) y 1 x 4 5) 4x – 3y = 15 2 Example 6 • Write an equation for the linear function f with the given values f(6) = -4, f(9) = -9 • Two lines in the same plane are parallel if they do not intersect. • Parallel lines have the same slope. • Two lines in the same plane are perpendicular if they intersect to form a right angle. • Perpendicular lines have slopes that are opposite reciprocals. Example 7 • Tell whether the following graphs are parallel, perpendicular, or neither. y = 2x + 4 4x + 2y = 12 Example 8 • Tell whether the following graphs are parallel, perpendicular, or neither. 3x + 4y = 24 -4x + 3y = 20