Notes on Slope-Intercept Form Essential Question: What does the slope of a line indicate about the line? Benchmark: “The student will be able to…” Determine the slope, x-intercept and y-intercept of a line given its graph, its equation, or two points on the line. Learning Goal: “The student will be able to understand…” Use coordinate geometry to find slopes, parallel lines, perpendicular lines, and equations of lines. Learning Activity: “We will learn this by…” Notes on Slope-Intercept Form

Slope-Intercept Form is an equation written in the form: Notes on Slope-Intercept Form Slope-Intercept Form is an equation written in the form: y = mx + b m = slope and b = y-intercept. y = 2x + 7 y = ½x - 4 Write an equation of the line with a slope of 4 and y-intercept of -2. m = 2 m = ½ y = 4x – 2 b = 7 b = -4

Write an equation of the line shown in the graph. Y2 – Y1 m = X2 – X1 (0,3) b = 3 3 – (1) m = 0 – 2 (2,-1) 4 m = or -2 -2 y = mx + b y = -2x + 3

Write in Slope-Intercept form and identify the slope and y-int Steps: (3,-4) (-1,4) x1 y1 x2 y2 1st – Calculate the slope 2nd – Plug in either point to get the value of “b” Y2 – Y1 y = mx + b m = X2 – X1 y = -2x + 2 y = -2x + b 4 – (-4) m = -1 – 3 -4 = -2(3) + b 4 + 4 m = -4 = -6 + b -1 + (-3) +6 +6 8 2 = b m = = -2 -4

Write in Slope-Intercept form and identify the slope and y-int Steps: (5,1) (-1,-5) x1 y1 x2 y2 1st – Calculate the slope 2nd – Plug in either point to get the value of “b” Y2 – Y1 y = mx + b m = X2 – X1 y = x + 4 y = x + b -5 – 1 m = -1 – 5 5 = 1 + b -5 + (-1) -1 -1 m = -1 + (-5) 4 = b -6 m = = 1 -6

Graph 5x - 3y = 6 y = mx + b 5x – 3y = 6 -5x -5x -3y = -5x + 6 -3 -3 (3,3) -5x -5x -3y = -5x + 6 (0,-2) -3 -3 5 y = x - 2 3

Write in Slope-Intercept form and identify the slope and y-int y = mx + b y = mx + b y = mx + b 2x + y = 3 6x + 3y = -9 12x – 3y = 6 -2x -2x -6x -6x -12x -12x y = -2x + 3 3y = -6x - 9 -3y = -12x + 6 3 3 -3 -3 m = 2 b = 3 y = -2x - 9 y = 4x - 2 m = -2 m = 4 b = -9 b = -2