7th1.5 - Mathmatuch

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Transcript 7th1.5 - Mathmatuch

Do Now 9/19/12
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Take out HW from Friday.
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Copy HW in your planner.
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Text p. 24, #7-20 all, 22-30 evens, 36 & 37
Text p. 28, #8-24 evens, #17, 35, & 36
Quiz sections 1.3 - 1.5 Wednesday
Chapter 1 Test Friday
Be ready to copy POTW#2.
Homework
Text p. 24, #7-20 all, 22-30 evens, 36 & 37
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7) 5 + x
8) y – 2
9) n ÷ 8
10) 9n
11) 3y – 10
12) 45 ÷ v
13) 5 + 2t
14) m + 6n
15) (23 ÷ u) – t
16) 6k – 14
17) 2(y + 5)
18) 100 ÷ (6 + w)
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19) 35(r – 45)
20) a. 17n
b. 68 pounds
22) h plus 3
24) s minus 405
26) 5 times the quantity a
minus 8
28) the quantity r plus 1
divided by 14
30) 8m
36) B
37) (104 + 19 · 2)x; $426
Objective
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SWBAT identify the parts of variable
expressions
In your notebook, compare and contrast a mathematical
expression (number sentence) and a regular “word”
sentence.
For example: “5 + 8 + 4 ”
and
“See spot run.”
Section 1.5 “Simplifying Algebraic Expressions”
Parts of an Expression
7x + 9y + 15
Terms
a number, variable, or product
of numbers and variables that
are always separated by
addition signs
The terms of
the expression
are 7x, 9y, and
15
Parts of an Expression
Coefficient
a number that is
multiplied by a variable
in an expression
3x + 5x + 8 + 1y
The coefficients of the
expression are 3, 5,
and 1
The coefficient is
always 1 for a
variable with no
number in front of it.
Parts of an Expression
Like Terms
terms with the same
variables raised to the
same exponents
3x + 2x + 8
Identify the like terms.
12x² + 3 + 2x² + 7
Constant terms are like terms.
Identify the Like Terms
terms with the same variables
raised to the same exponents
t
2
3
3y³
7t
4.5y³
x²
5
8x² 2t
Like terms:
t , 2t, and 7t
2
3 and 5
3y³ and 4.5y³
x² and 8x²
Simplifying an Expression
Like Terms
terms with the same
variables raised to the
same exponents
3x + 2x + 8
You can simplify an expression by
COLLECTING LIKE
TERMS
5x + 8
Simplifying an Expression
2n + 9 + 4n + 3
2n + 4n + 9 + 3
Commutative
Property
6n + 12
COLLECT LIKE
TERMS
Simplifying an Expression
4n² + 7n + 1n²
n² + 9n
4n² + 1n² + 7n + 9n
5n² + 16n
The coefficient is
always 1 for a
variable with no
number in front
of it.
Commutative
Property
COLLECT LIKE
TERMS
Simplifying an Expression
5x³ + 3y + 7x³ - 2y – 4x²
Commutative
Property
5x³ + 7x³ + 3y – 2y – 4x²
COLLECT
LIKE
TERMS
12x³ + 1y – 4x²
Simplifying Expressions in
Geometry
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What is the perimeter of the trapezoid?
Perimeter is the
distance around a figure.
3x
Add together each of the sides.
2y
2y
5x
3x + 2y + 5x + 2y
(reorder terms)
3x + 5x + 2y + 2y
(combine like terms)
8x + 4y units
What Did You Learn Today?
Terms
of the expression
are separated by
addition signs
Coefficient
a number that is
multiplied by a
variable in an
expression
Like Terms
terms with the same
variables raised to the
same exponents
Constant
term that has
no variable
24
Homework
- Text p. 28, #8-24 evens, #17, 35, & 36
Simplify the Expression
A.
B.
C.
D.
3a + 2b + 7a
5b² + 7 + 10b²
A). 10a + 2b
B). 15b² + 7
2x – 7 + 16 – 3x
C). -x + 9 or
-1x + 9
x + y – 12y – 3x
D). -2x + (-11y) or
-2x – 11y