1. 3.1 Solving Systems By Graphing Or Substitution

2. * A system of equations is a collection of equations in the same variable. *A solution to a system is an ordered pair (x,y) that makes the system true. *The solution (x, y) is also the point of intersection for the graphs of the lines in the system.

6. c. 6x + 4y = 12 2y = 6 – 3x What type of solution to you get?

7. d.-x + 2y = 3 2x – 4y = - 6

8. e. x – y = 2 x + 2y = -6

9. f. 9x – 3y = 3 21x + 4 = 7y

11. y= -3x + 8 b. 3x + y = 8 18x + 2y = 4 Substitute into second equation

12. c. 7x + y = 6 5x – y = – 3 Solution (.25, 4.25) CI

14. IV. The solution of a system in three variables, such as in x, y, and z, is an ordered triple (x, y, z) Ex 1. x + y + z = 5 2x – 3y + z = - 2 4z = 8 z = 2

16. Ex 2. x – y – z = - 4 5x + 2y – 3z = 7 6z = - 24 z = - 4

17. Lesson Quiz