+ Unit 1 – First degree equations and inequalities Chapter 3 – Systems of Equation and Inequalities 3.1 – Solving Systems by Graphing

+ Today we will be reviewing how to: Solve systems of linear equations by graphing Determine whether a system of linear equations is consistent and independent, consistent and dependent, or inconsistent.

+ 3.1 – Solving Systems by Graphing System of Equations – two or more equations with the same variables. To solve, find the ordered pair that satisfies ALL of the equations

+ 3.1 – Solving Systems by Graphing Example 1 Solve the system of equations by graphing. x + y = 3 -2x + y = -6

+ 3.1 – Solving Systems by Graphing Example 2 Solve the system of equations by graphing. x – 2y = 0 x + y = 6

+ 3.1 – Solving Systems by Graphing Example 3 A service club is selling copies of its holiday cookbook to raise funds for a project. The printer’s set- up charge is $200, and each book costs $2 to print. The cookbooks will sell for $6 each. How many must the club sell before it makes a profit?

+ 3.1 – Solving Systems by Graphing Classifying Systems Consistent – at least one solution Independent – exactly one solution Dependent – infinite solutions Inconsistent – no solutions

+ 3.1 – Solving Systems by Graphing Example 4 Graph the system of equations and describe it as consistent and independent, consistent and dependent, or inconsistent. x – y = 5 x + 2y = -4

+ 3.1 – Solving Systems by Graphing Example 5 Graph the system of equations and describe it as consistent and dependent, consistent and independent, or inconsistent. 9x – 6y = -6 6x – 4y = -4

+ 3.1 – Solving Systems by Graphing Example 6 Graph the system of equations and describe it as consistent and independent, consistent and dependent, and inconsistent. 15x – 6y = 0 5x – 2y = 10

+ 3.1 – Solving Systems by Graphing

+ HOMEWORK Page 120 #13 – 25 odd, 27 – 32 all