1. Bell Work: Use a sheet of notebook paper.
Brent wants to buy a 60” LED Smart TV, so he opened a savings account and added money to it every month. The chart below shows the relationship between the number of months Brent has been saving and the total amount of money in his account.
Determine the rate of change for this relationship and explain what it means in terms of Brent’s savings account.
Number of Months
Total Savings 1
$160 4
$415 6
$585 9
$840 12
$1,095

4. 13-2C
Slope-Intercept Form

5. Explore

6. Vocabulary
Slope
Y-intercept – the point at which the graph crosses the y-axis (0,b)
X- intercept – the point at which the graph crosses the x axis (x, 0)
Slope-intercept form

7. Slope-Intercept Form
Reminder!!! Slope is the rate at which a line changes. It is represented by:

8. How to find slope and y-intercept
Put the equation into slope-intercept form
(y = mx +b) by solving for y.
Remember that the number next to the x is the SLOPE and the constant (the number added or subtracted) is the y intercept.

9. You Try
1. Find the slope of the equation: 2. What is the y-intercept of the equation above? Write the answer as a coordinate (x ,y).

10. How to graph from Slope-Intercept Form
Plot the y intercept (0,b).
Plot a second point by counting the from your first point.
Draw a line through the two points using a ruler.
Make sure it makes sense (Should it be a positive or negative slope? Is my slope too steep/flat?)
Note: You can also check by plugging in a point into your equation and looking to see if it falls on your line.

11. Example

12. You Try
Graph the following equation:
y = 3x - 2

13. Interpreting Slope

14. You Try
Height
Time