Chapter 4: Graphing Linear Equations

Warm-Up Find the slope and y intercept 2y+14x = 11 13x - y + 12 = 0 Evaluate the functions when x = 5 f(x) = 5-2x + 3 f(x) = 3-12x

4.1 Plot points on coordinate Plane

A(3,4) B(-5, 0) C(-7, -2)

4.2 Graph Linear Equations

Solve for Y Y = -3x +1 Y + 3x = 1

Solve for Y: Y = -3x +1 Y + 3x = 1 Make a table: X -1 1 Y 4 -2

Solve for Y: Make a table: Plot the points and draw a line Y + 3x = 1 -1 1 Y 4 -2 Plot the points and draw a line

4.3 Graph using intercepts

Find the intercepts Finding The X intercept -0.5x + 2y = -4 -0.5x + 2(0) = -4 (solve for x) X = -8 Finding The Y intercept -0.5(0) + 2y = -4 (solve for y) Y = 2

Find the intercepts Finding The X intercept -0.5x + 2y = -4 -0.5x + 2(0) = -4 (solve for x) X = -8 Finding The Y intercept -0.5(0) + 2y = -4 (solve for y) Y = 2 Plot the intercepts and connect the line

4.4 Find slope and rate of change

Find the slope of a line y2 - y1 Example: (2, -3) and (4, -4) x2 - x1 Example: (2, -3) and (4, -4) -4-(-3) -1 m = ------ = ---- 4-2 2

4.5 Graph using slope-intercept form

Graph the equation 2x + y = -1 Rewrite in Slope-Intercept Form: y= -2x - 1 Determine the slope and the y- intercept: m= -2, y= (0,-1)

Graph the equation 2x + y = -1 Rewrite in Slope-Intercept Form: y= -2x - 1 Determine the slope and the y- intercept: m= -2, y= (0,-1) Graph

4.6 Model direct variation

Graph the direct variation equation y = -2x 3 Same way as graphing slope-intercept form, but instead of starting from a y-intercept, you start at the origin, or (0,0)

4.7 Graph linear functions

Evaluate the function f(x) = -6x+5 when x = 3 f(3) = -6(3)+5 substitute the x’s with 3s f(3) = -18 +5 solve = -13

Homework: Page 275 #s 1, 3, 5, 9, 10, 12, 13, 15, 18-20