The document discusses linear equations and graphing. It provides examples of how to graph the linear equation 3x - y - 2 = 0 by finding the x-intercept and y-intercept. It also discusses using linear equations to model world population growth over time, finding the slope as the rate of increase, and using the line to predict future population levels. The key aspects covered are defining linear equations, finding intercepts to graph lines, using linear equations to model real world scenarios, and determining slope as a rate of change.

1. Graphing Linear EquationsPre-Calculus 411-3

2. World PopulationThe population in the world had reached 6 billion in 1999. The population is expected to reach 7 billion in October of this year.What is the average rate of increase?Can you predict the population in 2020. Graph this linear equation

3. Linear EquationAx + By + C = 0 Solutions of the linear equation are points on the graphX-interceptY-intercept

4. ExampleGraph 3x – y – 2 = 0 using the x- and y- intercepts Substitute 0 for y to find the x-intercept. Substitute 0 for x to find the y-intercept The line crosses the y- axis at (0, -2)The line crosses the x-axis at

5. SlopeRatio of ChangeThe rate of increase in the world population is the slope of the line you graphed.

6. Linear EquationsStandard Form Ax + By = CSlope- intercept FormY = mx + b

8. QuestionWhen is a linear equation not a function?Hint: see the four types of slopes When the slope is undefined, vertical line

9. Zeros of a functionThe x-intercepts, solutionsFound when F(x) = 00 = mx + bIf m does not equal 0, then solution is In a case where m = 0, f(x)=b and thus is a constant function, graph is a horizontal line.