1. December 4, 2012 Finding the slope and y-intercept of the line to write an equation Warm-up: 1.If f(x) = -4x + 5, find a) f(-8) and b) f(-2x – 3) 2.Write an equation for the following situation: A gym membership has an initial fee of $100 and a monthly fee of $25. Let x represent the months and y, the amount spent on the membership.

2. Two forms of a line: Slope Intercept Form and Function Form What we called it before: y = rate(x) + base Slope Intercept Form: y = mx + b Function Form: f(x) = mx + b Let’s look at the graphs and equations from HW 4.8

3. We can now identify the slope and y- intercept from a graph. y = mx + b (pick 2 points on the graph) y-intercept (base): when x = 0 and hits the y-axis

4. Identify the slope and y-intercept, then write the equation: y = mx + b Positive slope Negative slope

5. What is the slope and equation for horizontal and vertical lines?

6. Finding the slope between two points You only need two points to find the slope of a line. Find the slope between (5, 1) and (2, -3). Using a tableUsing a formula Try one more using any strategy: Find the slope between (2, 3) and (2, -3)