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12/5/11 §Bellringer: l What is the greatest common factor of 30 and 45? l If you did not finish your test, fill out your agenda to come back for E&R tomorrow!

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Presentation on theme: "12/5/11 §Bellringer: l What is the greatest common factor of 30 and 45? l If you did not finish your test, fill out your agenda to come back for E&R tomorrow!"— Presentation transcript:

1 12/5/11 §Bellringer: l What is the greatest common factor of 30 and 45? l If you did not finish your test, fill out your agenda to come back for E&R tomorrow!

2 Equations

3 Whatever you do to an equation, do the SAME thing to BOTH sides of that equation! Start with adding/subtracting then do multiplying/dividing. (Reverse order of operations) To get a number to cross out, do the opposite operation. You are trying to get x by itself to see what it equals!

4 Solve this equation for x: x + 3 = 8

5 Check: x + 3 = 8 5 + 3 = 8 8 = 8 true

6 Solve for x. x-4=10 5x=25 X = 10 4

7 http://video.google.com/videoplay?docid=- 799454014728007411# To 6:40

8 Solve this equation for x: 5x - 2 = 13

9 Check: 5x - 2 = 13 5(3) - 2 = 13 15 - 2 = 13 13 = 13 true

10 2x – 4 = 8

11 5x + 10 = 80

12 -3x – 4 = -82

13 12/6/11 §Get out your homework! §Bellringer: l Add WITHOUT A CALCULATOR!!! 5+6 -10+4 -3+7 -5+(-4) 4+(-6) 5+(-2)

14 Homework Answers 1.x=4 2.k=12 3.n=12 4.z=6

15 2/3x + 2 = 8

16 x/5 + 2 = 8

17 Worksheet

18 Get the goof- What did the person do wrong? Solve for x: 4x+12=76 -4 -4 x12=72 12 12 x = 6

19 Writing Equations Add- more than, increases by, sum Subtract- less, less than, difference, decreases by Multiplication- product, twice, times Division-quotient Equals- is Write in order of the words EXCEPT when it says less than! Switch the order for less than!

20 Worksheet Write into an equation and then solve. 1.Four more than twice a number is 8 3. Five less than twice a number is 7

21 15. Eight more than the quotient of a number and 5 is 3

22 Video http://video.google.com/videoplay?docid=- 799454014728007411# 6:40

23 Solve this equation for x: 4x + 5 = x - 4

24 Check: 4x + 5 = x - 4 4(-3) + 5 = -3 -4 -12 + 5 = -7 -7 = -7 true

25

26

27

28 7y + 5 - 3y + 1 = 2y + 2

29 Check: 7y + 5 - 3y + 1 = 2y + 2 7(-2) + 5 - 3(-2) + 1 = 2(-2) + 2 -14 + 5 + 6 + 1 = -4 + 2 -2 = -2 true

30 3(n - 1.8) = 2n + 1

31 Check: 3(n - 1.8) = 2n + 1 3(6.4 - 1.8) = 2(6.4) + 1 3(4.6) = 12.8 + 1 13.8 = 13.8 true

32 An inequality is like an equation, but instead of an equal sign (=) it has one of these signs: < : less than ≤ : less than or equal to > : greater than ≥ : greater than or equal to

33 Inequalities Solve the exact same way, but it has a instead of = If you multiply or divide by a negative number, switch the sign! When graphing, are open circles and ≤ and ≥ are closed circles. Color everything x could be.

34 “x < 5” means that whatever value x has, it must be less than 5. Try to name ten numbers that are less than 5!

35 Numbers less than 5 are to the left of 5 on the number line. 051015-20-15-10-5-252025 If you said 4, 3, 2, 1, 0, -1, -2, -3, etc., you are right. There are also numbers in between the integers, like 2.5, 1/2, -7.9, etc. The number 5 would not be a correct answer, though, because 5 is not less than 5.

36 “x ≥ -2” means that whatever value x has, it must be greater than or equal to -2. Try to name ten numbers that are greater than or equal to - 2!

37 Numbers greater than -2 are to the right of 5 on the number line. 051015-20-15-10-5-252025 If you said -1, 0, 1, 2, 3, 4, 5, etc., you are right. There are also numbers in between the integers, like -1/2, 0.2, 3.1, 5.5, etc. The number -2 would also be a correct answer, because of the phrase, “or equal to”. -2

38 Examples Graph x > 7 Graph -4 ≥ x Since the sign is >, we put an OPEN circle on 7. X is greater than 7 so we color up the number line. Since the sign is ≥ we put a CLOSED circle on -4. X is smaller than -4 so we color down the number line.

39 Solving One-Step Inequalities

40 6) Solve x -14 < 16 x - 14 < 16 + 14 + 14 x < 30 30 -14 = 16 16 = 16 Solve this problem like an equation 1.Draw “the line” 2.Add 14 to both sides 3.Simplify 4.Check your answer 5.Graph the solution o 303129

41 8) Solve 8y + 3 > 9y - 14 o 171816 - 8y - 8y 3 > y - 14 + 14 + 14 17 > y y < 17 8(17) + 3 = 9(17) - 14 1.Draw “the line” 2.Subtract 8y from both sides 3.Simplify 4.Add 14 to both sides 5.Simplify 6.Rewrite inequality with the variable first 7.Check your answer 8.Graph the solution

42 Solve for x: ( x / 3 ) > -4 Solve for x: 6x > 36

43 Inequalities If you multiply or divide by a negative number, the sign changes!

44 Examples of when to switch signs -3x+4 > 21 X – 7 < 45 -2

45 Solving One-Step Inequalities

46 Writing Inequalities You have at least 35 minutes to complete your quiz. The speed limit is 55 mph. At the most, you can spend $50.

47 Worksheet

48 Metropolis Gas and Power charges their customers a monthly service charge of $13.60 and a volume charge of $1.59 for every 100 cubic feet of natural gas used. Which of the following equations could be used to find Bruce Wayne's monthly gas bill? (Let x represent the number of cubic feet of gas used in hundreds and y represent the total monthly cost.)

49 7 - x < 6 What is the first step when solving the equation for x? ( 1 / 5 ) (6x + 4) = 4x Solve for x. x / 4 - 9 = 5

50 Study Island www.studyisland.com Click on Nolan Period ____ Click on equations. Complete 10 questions in test mode. When you finish with equations work on Inequalities. Turn scratch paper into basket. This is a grade!!!! Test on Monday!


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