3. Rate of Change Rate of change = It costs $______ per day. Change in y Change in x 140 5 120 4 100 3 80 2 60 1 Rental Charge # of days
4. Rate of Change Rate of change = It costs $______ per mile. Change in y Change in x 78 300 66 250 54 200 42 150 30 100 Fee Charged Miles
5. You try! After every 1 day, the price decreases by $______. For every 1 person, the price is $______. 1. 2. 75 5 90 4 105 3 120 2 135 1 Amount Owed Day 23.70 6 19.75 5 15.80 4 11.85 3 7.90 2 Cost People
6. Slope The Rate of Change of a line is called its SLOPE. If you are given two sets of points, (x 1 , y 1 ) and (x 2 , y 2 ) you can find the slope using the formula above. rise run Slope = y 2 – y 1 x 2 – x 1 =
7. Find the slope of the line through A(-2 , 1) and B(5 , 7) Find the slope of the line through A(-1 , 3) and B(7 , 9) rise run Slope = y 2 – y 1 x 2 – x 1 =
8. Find the slope of the line through A(1 , 2) and B(7 , 4) Find the slope of the line through A(0 , 5) and B(6 , -7) Find the slope of the line through A(-2 , 4) and B(0 , -6) You try!
9. Slope = Graph the ordered pair: (-1 , 0) and (1 , 3) What is the slope? rise run
10. Slope = Graph the ordered pair: (2 , 2) and (-4 , 6) What is the slope? rise run
11. Slope = Graph the ordered pair: (0 , -2) and (-1 , 2) What is the slope? You try! Graph the ordered pair: (-1 , -3) and (1 , 5) What is the slope? rise run
12. Slopes of Lines Horizontal Lines Find the slope of the line through (1, 2) and (4, 2). The slope of a horizontal line is always 0.
13. Slopes of Lines Vertical Lines Find the slope of the line through (4, 2) and (4, -1). The slope of a vertical line is always undefined.
14. Positive and Negative Slopes If m > 0, then the line will slant upward from left to right. If m < 0, then the line will slant downward from left to right.
15. State whether each line is horizontal, vertical, has a positive slope, or a negative slope. 1. 2. 3. 4.