3.4 Opening Activity: Draw a graph of the equation y = 5x + 20 What are the x and y intercepts? (write your answers as coordinates). How are you able to use the equation but NOT the graph to find the x and y intercepts? x-intercept plug in zero for y 0=-5x+20 subtract 20-20=-5x divide by -5 4=x (4,0) y-intercept plug in zero for x y=-5(0)+20 y=20 (0, 20)
3.4 3.4 The Graph of Ax + By = C Objectives: Determine the Intercepts of a linear combination situation. Understand the meaning of the intercepts in the context of the situation. Graph a linear combination situation using it's intercepts. Determine the slope of a linear combination graph.
3.4 Opie is allowed to spend 80% of his birthday money and 20% of his chore money. The remaining he must save in his savings account. If x is the amount of money he gets for his birthday, then what expression represents how much of his birthday money he can spend? If y is the amount of money he earns from doing chores, then what expression would represent the amount of his chore money he can spend? What expression represents the total amount of money that Opie can spend from his birthday money and chore money combined?
3.4 Opie is allowed to spend 80% of his birthday money and 20% of his chore money. The remaining he must save in his savings account. Opie wants to spend $17 on a lego set. If x represents the amount of birthday money he gets, and y represents the amount of chore money he earns, then what equation would model this situation?
3.4 Opie is allowed to spend 80% of his birthday money and 20% of his chore money. The remaining he must save in his savings account. Opie wants to spend $17 on a lego set. If x represents the amount of birthday money he gets, and y represents the amount of chore money he earns, then what equation would model this situation? If Opie doesn't get any birthday money, then how much chore money does he need to earn in order to buy the lego set? If Opie doesn't do any chores, then how much money does he need to get for his birthday in order to buy the lego set? Write these two answers as coordinates.
Opie is allowed to spend 80% of his birthday money and 20% of his chore money. The remaining he must save in his savings account. Opie wants to spend $17 on a lego set. If x represents the amount of birthday money he gets, and y represents the amount of chore money he earns, then what equation would model this situation? Draw a graph of this situation. Amount of Chore Money What is the slope of this line? Amount of Birthday Money
3.4 A ten inch pizza will serve 2 people. An eighteen inch pizza will serve 4 people. Write an equation for the number of ten inch pizzas (x) and the number of eighteen inch pizzas (y) that it could take to serve 36 people. How many people will x ten inch pizzas feed? How many people will y eighteen inch pizzas feed?
3.4 A ten inch pizza will serve 2 people. An eighteen inch pizza will serve 4 people. Write an equation for the number of ten inch pizzas (x) and the number of eighteen inch pizzas (y) that it could take to serve 36 people. How many ten inch pizzas would you need if you ordered 0 eighteen inch pizzas? How many eighteen inch pizzas would you need if you ordered 0 ten inch pizzas? Graph this linear combination situation.
10 10 12 14 3.5 Opening Activity: State everything you know about the following graph. Amount of Chore Money 2 4 6 8 2 4 6 8 Amount of Birthday Money
3.5 & 3.6 Finding an equation of a line. Objectives: Given two points on a line, find the slope and utilize point slope form of a line. Given many points on a line, choose the best two points to use to find equation. Use a regression calculator to find a best fit equation.
12 10 3.5 8 Connecting which two dots would create a line that best represents the data? 6 4 2 2 4 6 8 10 12 14
3.5 What is needed in order to write an equation in slope intercept form? What is the slope of the line between the points (2, 3) and (11, 7)? What is the y intercept of the line that passes through the points (2, 3) and (11, 7)?
3.5 Point Slope form of a line A line with slope m and passing through the point (x 1, y 1 ) can be written as: y y 1 = m(x x 1 ) Write the equation of the line that passes through the points (2, 3) and (11, 7) in pointslope form. Simplify and solve this equation for y so it is in slope intercept form.
3.5 A number between 1 and 1 represents the linear dependence between two variables a statistical measure of degree that changes the value of one variable a related phrase would be line of best fit. a relationship a statistical measure of the relationship between two variables. measuring data represents the linear dependence. google dictionary a number between 1 and 1 calculated to represent the linear dependency of two variables or a set of data If there is no line it is just zero. called r Use the internet to find out what a correlation coefficient is? On one side of a piece of paper, make a list of phrases that describes correlation coefficient. On the other side of the same paper, draw a picture without words that describes correlation coefficient. Why is it between 1 and 1?
3.6 Watch this video, then perform the same task on your calculator with the following data: x y 1 15 2 16 3 19 4 18 5 25 http://bit.ly/2acawag What is the equation that best models the data? What is the correlation coefficient? Is this a perfect correlation?