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Wednesday, September 4 th Please complete the warm up . Solve: -(x+3)=5 + 2(4x-20) Solve:. Joke of the Day. How do equations get into shape?!?! They do multi-step aerobics. Homework Answers. Around the World. Fraction Coefficients. Don’t forget to: FLIP The coefficient. 1. 2. - PowerPoint PPT Presentation
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Wednesday, September 4th
Please complete the warm up
1. Solve: -(x+3)=5 + 2(4x-20)
2. Solve:
2465
1 xx
Joke of the Day
How do equations get into shape?!?!
They do multi-step aerobics
Homework Answers
Around the World
Fraction Coefficients
1.
2.
3.
525
7x
21 9
3k
84 319w
Don’t forget to:
FLIPThe
coefficient
What Did the Superman Do Wrong?!?!
-(x – 4) = -3x - 7 + 5x
-x – 4 = 8x + 7
-4=7x + 7
-11 = 7x
-11/7 = x
What Did the Sponge Bob Do Wrong?!?!
312
4x
1 3
12 4x
3
48x
Helpful Hint
Equations are often easier to solve when the variable has a positive coefficient. Keep this in mind when deciding on which side to "collect" variable terms.
Let’s Practice
What would I do to keep the coefficient Positive?
1. 7a – 17 = 4a + 12. 2b – 5 = 8b + 1 3. 4x – 2 = 3x + 44. 2x -5 = 4x – 1 5. 5x + 2 = 3x
You’ve got to Practice!
Let’s get warmed Up!
1. –4 + 7x = 3
2. 6 – 7(a + 1) = –3(2 – a
3.
4 – 6a + 4a = –1 – 5(7 – 2a)
Challenge Problem
Combine like terms.
Distribute –5 to the expression in parentheses.
4 – 6a + 4a = –1 –5(7 – 2a)
4 – 6a + 4a = –1 –5(7) –5(–2a)
4 – 6a + 4a = –1 – 35 + 10a
4 – 2a = –36 + 10a
+36 +36
40 – 2a = 10a+ 2a +2a
40 = 12a
Since –36 is added to 10a, add 36 to both sides.
To collect the variable terms on one side, add 2a to both sides.
ANY QUESTIONS BEFORE WE GO FURTHER…..
Graphing and Solving Inequalities
1. An inequality is a statement that two quantities are not equal. The quantities are compared by using the following signs:
≤A ≤ B
A is less than or
equal to B.
<A < B
A is lessthan B.
>A > B
A is greaterthan B.
≥A ≥ B
A is greaterthan or
equal to B.
≠A ≠ B
A is notequal to B.
2. A solution of an inequality is any value that makes the inequality true.
Vocabulary
An inequality like x < 6 has too many solutions to list. You can use a graph on a number line to show all the solutions.
The solutions are shaded and an arrow shows that the solutions continue past those shown on the graph. To show that an endpoint is a solution, draw a solid circle at the number. To show an endpoint is not a solution, draw an empty circle.
Graphing Inequalities
Don't Shade Shade< Less than
Example: x<4
> Greater than
Example: x > 5
≤ Less than OR equal to
Example: x ≤5
≥ Greater than OR equal to
Example: x ≥6
To Shade or Not to Shade
o
o
Words ExampleD: Draw a number line
and a circle at the endpoint
I: Include? To shade or not to shade!
S: Shade in the correct direction
C: Check: substitute a value on the solution and check to see if it’s true
x <4
D:
I:
S:
Check: Is -5 less than 4?
Steps to Graphing Inequalities: DISC
o
Example of Graphing Inequalities
Graph each inequality.
A. m ≥
0 1– 2 3 3
Draw a solid circle at .
Shade all the numbers
greater than and draw an
arrow pointing to the right.B. t < 5(–1 + 3)
t < 5(–1 + 3)
t < 5(2)
t < 10
–4 –2 0 2 4 6 8 10 12 –6 –8
Simplify.
Draw an empty circle at 10.Shade all the numbers less than 10 and draw an arrow pointing to the left.
Reading Math
•“No more than” means “less than or equal to.”
•“At least” means “greater than or equal to”.
Page 31 IMN
Solving one-step inequalities is much like solving one-step equations. To solve an inequality, you need to isolate the variable using the properties of inequality and inverse operations.
Guess What?!?!
Using Addition and Subtraction to Solve Inequalities
Solve the inequality and graph the solutions.
x + 12 < 20
x + 12 < 20
–12 –12
x + 0 < 8
x < 8
Since 12 is added to x, subtract 12 from both sides to undo the addition.
–10 –8 –6 –4 –2 0 2 4 6 8 10
Draw an empty circle at 8.
Shade all numbers less than 8 and draw an arrow pointing to the left.
Multiplying or Dividing by a Positive Number
Solve the inequality and graph the solutions.
7x > –42
7x > –42
>
1x > –6
Since x is multiplied by 7, divide both sides by 7 to undo the multiplication.
x > –6
–10 –8 –6 –4 –2 0 2 4 6 8 10
r < 16
0 2 4 6 8 10 12 14 16 18 20
Since r is multiplied by ,
multiply both sides by the
reciprocal of .
Multiplying or Dividing by a Positive Number
Solve the inequality and graph the solutions.
MOST IMPORTANT
PART OF TODAY!!!!!!!!!!
If you multiply or divide both
sides of an inequality by a negative number, the resulting inequality is not a
true statement. You need to reverse the inequality symbol to make the statement true.
Multiplying or Dividing by a Negative Number
Solve the inequality and graph the solutions.–12x > 84
x < –7
Since x is multiplied by –12, divide both sides by –12. Change > to <.
–10 –8 –6 –4 –2 0 2 4 6–12–14
–7
Caution! Do not change the direction of the inequality symbol just because you see a negative sign. For example, you do not change the symbol when solving 4x < –24.
I. Solving Multi-Step InequalitiesPage 5 IMN
Solve the inequality and graph the solutions.
45 + 2b > 61
45 + 2b > 61–45 –45
2b > 16
b > 8
0 2 4 6 8 10 12 14 16 18 20
Since 45 is added to 2b, subtract 45 from both sides to undo the addition.
Since b is multiplied by 2, divide both sides by 2 to undo the multiplication.
#1
8 – 3y ≥ 298 – 3y ≥ 29–8 –8
–3y ≥ 21
y ≤ –7
Since 8 is added to –3y, subtract 8 from both sides to undo the addition.
Since y is multiplied by –3, divide both sides by –3 to undo the multiplication. Change ≥ to ≤.
–10 –8 –6 –4 –2 0 2 4 6 8 10
–7
#2
KeepPracticing
!
–12 ≥ 3x + 6–12 ≥ 3x + 6– 6 – 6
–18 ≥ 3x
–6 ≥ x
Since 6 is added to 3x, subtract 6 from both sides to undo the addition.
Since x is multiplied by 3, divide both sides by 3 to undo the multiplication.
–10 –8 –6 –4 –2 0 2 4 6 8 10
#3
x≤-6
Make sure variable is on
the left!!!
x < –11
–5 –5x + 5 < –6
–20 –12 –8 –4–16 0
–11
Since x is divided by –2, multiply both sides by –2 to undo the division. Change > to <.
Since 5 is added to x, subtract 5 from both sides to undo the addition.
#4You try!!!
3 + 2(x + 4) > 33 + 2(x + 4) > 3
3 + 2x + 8 > 3
2x + 11 > 3– 11 – 11
2x > –8
x > –4
Distribute 2 on the left side.
Combine like terms.Since 11 is added to 2x, subtract
11 from both sides to undo the addition.
Since x is multiplied by 2, divide both sides by 2 to undo the multiplication.
–10 –8 –6 –4 –2 0 2 4 6 8 10
#5You try!!!Take it step by step