1. Please write down the HW for the week. Then, take out only a pencil.

2. Eagle Concession Stand
Work with a partner.
Find the cost of each individual item.
Find the total cost of 1 slice of pizza, 1 soda, and 1 ice cream.
Let’s share strategies…

3. a.k.a. systems of equations
Simultaneous
EQUATIONs
a.k.a. systems of equations
EQ: How do you determine the number of solutions for a system of equations?

4. Baseball Souvenir Shop
Work with your partner to find the cost of each individual item.
Let’s share strategies.
Write on the back about what you did.

5. Try it: Think of an ordered pair that is a solution to y = x + 1.
Compare with a partner. Is your solution the same? Should it be? Why or why not?
Note: There are infinitely many solutions to this equation. Can you come up with 3 more?

6. Keep it going:
Now that you found solutions to y = x + 1, can you find which of these solutions will also work in y = 5 – x?
How many ordered pairs did you find that work in both equations?

7. SYSTEM OF EQUATIONS Ex: y = x + 1 y = 5 – x
A system consists of two or more __________ and will contain two or more __________.
A solution to a system of equations is an ________ ________ that works in both equations.
Ordered
Pair
Equations
Variables

8. Thumbs up/down…
Is (6, -2) a solution to 2x – y = 14 and x + 4y = -2?
Is (4, 0) a solution to x – 2y = 4 and –x + y = -8?
yes no

9. We will….. Learn 3 different methods to find that order pair.
Will there be exactly 1 ordered pair for ALL the sets of equations? NO

10. Remember – you can only use TWO lines.
In pairs:
How many times can 2 straight lines intersect? What if you draw it differently?
Remember – you can only use TWO lines.
Can two lines only intersect at one spot?
What if the lines are parallel?
What if a line lies right on top of another line?

11. Types of systems of equations:
A system with no solutions is called _____________. These lines are parallel.
A system that has a solution is called _____________.
There are two types:
One solution Infinitely Many Solutions
(Intersect at 1 point) (Line on top of a line)
Inconsistent
Consistent
Independent
Dependent

12. Discuss with a partner:
Describe a “solution to a system of linear equations.” (define)

13. Homework p. 386 # 8 – 11 all Remember…
A solution to linear system means it must make a true statement in BOTH equations.

14. y = ½ x – 3 and -2x + y = -10? Show work to support your answer.
1/30/13
Is (6, 0) a solution to
y = ½ x – 3 and -2x + y = -10? Show work to support your answer.
HW check
today! NO

15. Review with a partner… How would you graph y = 2x – 7?

16. Graphing Linear Systems
Mrs. Spanier
Algebra 1

17. To find the solution to a system…
Graph the first line.
Graph the second line.
Look for the point where they intersect each other.
This is the solution! (ordered pair)

18. Jigsaw: Find the solution for each system (on back of GO).
y = 2; y = 4x – 2
y = -½x + 4; y = -½x – 2
2x + 3y = -6; y = ¼x + 3
y = 3x – 5; -6x + 2y = -10
(1, 2)
No solution
(-6, 2)
Infinitely many solutions

19. Solve by graphing: (1, 6) (1, -3) y = 2x + 4; y = -x + 7
y = 4x – 7; x + y = -2
(1, 6)
(1, -3)

20. HW Worksheet Answers (2, 1) (2, 4) (-5, 12) (-1, -1)
No solution (parallel)
(1, 6)

21. HW 6-1 WS (20 months, $500) (14 months, 75 books) C G B F Point
estimates
should
be close
(20 months, $500)
(14 months, 75 books) C G B F