Lesson 5-2 – Slope Intercept Form Notes – Writing Linear Equation Agenda Lesson 5-2 – Slope Intercept Form Standards 6.0 Graph a linear equation 7.0 Verify that a point lies on a line, given an equation of the line Warm Up Review Notes – Writing Linear Equation Practice Homework – Page 242 problems 7 to 9 and 19 to 21

Homework – Page 242 problems 7 to 9 and 19 to 21 Warm Up Find the slope for the lines that contain the following pairs of points a. (2, 3) and (4, 7) b. (3, 1) and (4, –2) c. (2, 4) and (2, 6) d. (4, 4) and (2, 4) Homework – Page 242 problems 7 to 9 and 19 to 21

Find the missing coordinate EXAMPLE A Find the missing coordinate (2, 4), (x, 8); slope = –2 m = y2 – y1 x2 – x1 -2x + 4 = 4 –4 –4 -2x = 0 -2 = 8 – 4 x – 2 -2x = 0 -2 -2 -2 = 4 x – 2 -2(x – 2) = (x – 2) x = 0 -2(x – 2) = 4 (2, 4), (0, 8) -2x + 4 = 4

Linear function: a function that graphs a line. Slope-Intercept Form Linear function: a function that graphs a line. Parent function: simplest equation of a function Examples: y = x, y = x2 Linear equation: an equation that models a linear function y-intercept: the y-coordinate of the point where the line crosses the y-axis Slope-intercept form: y = mx + b Slope y-intercept

Identifying Slope and y-Intercept EXAMPLE 1 Identifying Slope and y-Intercept What is the slope and y-intercept of y = 3x – 5? Use: y = mx + b Rewrite: y = 3x – 5 as y = 3x + (–5) slope y-intercept

2 EXAMPLE Writing an Equation Use: y = mx + b m = 2 and b = 6 Write an equation of the line with slope 2 and a y-intercept 6 Use: y = mx + b m = 2 and b = 6 Substitute m = 2 and b = 6 in y = mx + b to get y = 2x + 6

Writing an Equation from a graph EXAMPLE 3 Writing an Equation from a graph y- intercept = ______ slope = = rise run

Class work – Please do these now Page 242 Problems 1 to 6 all, 10 to 18 even and 22 to 26 even Homework – Please do at home Page 242 problems 7 to 9 and 19 to 21 all

Lesson 5-2 – Slope-Intercept Form - Day 2 Agenda Lesson 5-2 – Slope-Intercept Form - Day 2 Standards 6.0 Graph a linear equation 7.0 Verify that a point lies on a line, given an equation of a line Warm Up Review Notes – Slope Practice Homework – Page 217 problems 20 to 28 all

Verifying Points on a Line EXAMPLE 4 Verifying Points on a Line Determine whether (3, –5) lies on the graph of y = –3x + 4 y = –3x + 4 –5 = –3(3) + 4 ? –5 = –9 + 4 ? –5 = –5

You Try One: Determine whether (5, –7) lies on the graph of 3y + 5x = 4

5 EXAMPLE Graphing an Equation You buy vegetables at a farmer’s market for $1.50 per pound. The equation y = 1.5x represents the situation where y is the number of pounds and y is the total cost of your purchase. Graph the equation. Step 1 The y-intercept is 0. so plot A point a (0, 0) Step 3 Draw a line through the two points. Step 2 The slope is 1.5 or . Use the slope to plot a second point 3 2

Class work – Please do these now Page 242/243 Problems 28 to 42 even and 47 to 52 all Homework – Please do at home Page 242/243problems 43 to 45 and 53 to 55 all