Writing Equations From Two Points (In China!)

Materials Needs Pencil Notebook Scissors Glue Passport Planner Laptop

Table of Contents Pg Title 24 Warm Up, Guided Practice 25 Writing Equations From Two Points Notes

Warm-Up Write an equation in slope-intercept form with the given information m = -6; point: (3, -2) m = 0; point: (-7, 1)

Forbidden City, Beijing, China

Learning Intention/Success Criteria LI: We are learning to write linear equations using two points. SC: I know how to 1. use the slope formula to find the slope between two points 2. write linear equations in slope intercept form 3. substitute values into equations 4. identify x, y, m, and b values 5. simplify expressions 6. solve multi-step equations for a variable

Today’s Vocabulary Slope Formula m = change in y change in x m = y2 – y1 x2 – x1

Revisited Vocabulary Slope A number which is used to indicate the steepness of a line Indicates if the line is tilted uphill or downhill Indicated by the letter “m” Point The pair of numbers giving the location on the coordinate plane Written in the form: (x, y)

Revisited Vocabulary Y-Intercept The point at which the function crosses the y-axis Indicated by the letter “b” Slope Intercept Form A way of writing an equation with a slope and y-intercept Written: f(x) = mx + b

Example 1: Find the equation of the line in slope intercept form that passes through (3, 1) and (-4, 15) m = y2 – y1 x2 – x1 SC1 SC3 SC5 m = 15 – 1 -4 – 3 = 14 -7 = -2 SC2 y = mx + b SC3 SC4 1 = (-2)(3) + b 1 = -6 + b SC5 ______________ +6 +6 SC6 7 = b SC2 y = -2x + 7

Guided Practice 1 Using slope-intercept form, find the equation of the line that passes through (2, -5) and (8, 13)

Guided Practice 1 Using slope-intercept form, find the equation of the line that passes through (2, -5) and (8, 13) m = y2 – y1 x2 – x1 = 13 – (-5) 8 – 2 = 18 6 = 3 y = mx + b y = 3x – 11 13 = (3)(8) + b 13 = 24 + b -11 = b

Guided Practice 2 Using slope-intercept form, find the equation of the line that passes through (4, -1) and (-2, 29)

Guided Practice 2 Using slope-intercept form, find the equation of the line that passes through (4, -1) and (-2, 29) m = y2 – y1 x2 – x1 = 29 – (-1) – 2 – 4 = 30 -6 = -5 y = mx + b y = -5x + 19 -1 = (-5)(4) + b -1 = -20 + b 19 = b

Game Time! With your country group, take out the Kings and Queens in your deck and place them on the side Ace is 1. Jack is 0 Red = Negative. Black = Positive

Game Time! Each person at your country will pick 1 card (with a total of 4 cards) The first two cards drawn are for Point 1. The second two cards drawn are for Point 2 Using this information, find the equation of the line First person to get the line solved correctly, gets a point

Game Time! First person to get the equation correct gets a point Person with the most points wins Everyone in your group must get the same answer before moving on to the next problem

Passport Stamp You’re hanging out in the forbidden city. Which Palace represents your learning? Explain your reasoning. Palace of Eternal Longevity Palace of Universal Happiness Palace of Prolonged Happiness Palace of Great Brilliance Palace of Eternal Harmony