Download 01 Writing Expressions and Equations.notebook

01 Writing Expressions and Equations.notebook
September 04, 2013
Warm Up!!
Evaluate:
2. 23 ­ 31
1. 17 ­ 9
Tap
-8
8
Tap
4.
3. 42÷ 6
4Tap
7
Tap
Today's Lesson: §1-1 Writing Expressions & Equations
Variable: A letter that represents a number.
Examples: x, y, z, etc.
Algebraic Expression: Consists of one or more numbers and
variables along with one or more arithmetic operations.
Examples: a + 2
7x - 3
5mn/3k
Numeric expression: contains only numbers and
mathematical operations (+/-/*/
÷)
Examples: 6 + 2 ÷ 1
4x5x8
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01 Writing Expressions and Equations.notebook
September 04, 2013
Factors: the quantities being multiplied.
Product: the result of factors multiplied together
Examples:
(2)(3)
The factors are: 2, 3
The product is:
6
3(xy)
The factors are: 3, x, y
The product is:
3xy
2m(5x)
The factors are: 2, m, 5, x
The product is:
10mx
Translating Words to Mathematics:
Match!
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01 Writing Expressions and Equations.notebook
September 04, 2013
Translating Words to Mathematics:
Match!
Important Information to Remember:
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01 Writing Expressions and Equations.notebook
September 04, 2013
Write the Algebraic Expression for the
given Verbal Expression
Verbal Expression
Algebraic Expression
7 less than
the product of 3 and a number x
3x - 7
the product of 7 and a
divided by the product of 8 and y
7s ÷ 8y
four years younger than Sarah
(Let "s" stand for Sarah's age)
S - 4
half as big as last night's crowd
(Let "c" stand for last night's crowd)
A python eats 4 pounds of meat each month.
1. Write a numeric expression that represents how much meat a python eats in 5 months.
4x5
4 5
OR
4(5)
2. Write an algebraic expression that represents how much meat a python eats in "x" months.
4 x
BETTER
4x
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01 Writing Expressions and Equations.notebook
September 04, 2013
Tips to remember:
1) Letters in algebra are called variables because their
values can vary.
2) When multiplying a number and a variable, the number is
written first .
For example: x times 5 is 5x NOT x5.
3) Don't use subtraction in the wrong order!
For example: "the difference of 5 and t"
and: "5 decreased by t"
are translated as 5 - t
while: "5 less than t"
and: "5 subtracted from t"
are translated as t - 5 .
Write the Verbal Expression for the given
Algebraic Expression
Verbal Expression
Algebraic Expression
x ÷8
g + 5
x - y
3y - 4 5
01 Writing Expressions and Equations.notebook
September 04, 2013
Equation
Expression
1. An expression is a
sentence fragment
or a phrase
1. An equation is a
complete sentence
2. An equation can be
simplified & solved
2. An expression can be
simplified
3. An expression does NOT have
an equal sign or an inequality
symbol (no < or > symbol),
therefore it
cannot be solved!
3. An equation has an equal sign
Translating Words to Mathematics: Match!
Typo on Notes :(
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01 Writing Expressions and Equations.notebook
September 04, 2013
Write an algebraic equation for each sentence.
3
(mult)
x
=
21
3x = 21
1. Three times a number equals 21.
(divide)
x
8
=
20
2. The quotient of a number and 8 is 20.
(minus &
switch order)
x
(two times)
=
31
3. Seven less than twice a number is equal to 31.
2x - 7 = 31
Grouping Symbols:
• Parentheses are known as grouping symbols in algebra. • The words "the quantity" are interpreted algebraically as parenthesis.
• For example: Three times the quantity six minus two is twelve.
Means: 3(6 - 2) = 12
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01 Writing Expressions and Equations.notebook
September 04, 2013
Match the Sentence with the Algebraic Equation:
1. Two less than five times "d" is "r".
5d ­ 2 = r
2. Twice the quantity five less than "d" is equal to "r".
2(d ­ 5) = r
3. The product of two and "d" decreased by five equals "r".
2d ­ 5 = r
4. The product of two and the quantity "d" less than five is "r".
2(d ­ 5) = r
5. Five times the quantity "d" subtracted from two is "r".
5(2 ­ d) = r
6. Two times five minus "d" is equal to "r".
2(5) ­ d = r
check
Match the Sentence with the Algebraic Equation:
1. Two less than five times "d" is "r".
5d ­ 2 = r
2. Twice the quantity five less than "d" is equal to "r".
2(d ­ 5) = r
3. The product of two and "d" decreased by five equals "r".
2d ­ 5 = r
4. The product of two and the quantity "d" less than five is "r".
2(d ­ 5) = r
5. Five times the quantity "d" subtracted from two is "r".
5(2 ­ d) = r
6. Two times five minus "d" is equal to "r".
2(5) ­ d = r
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01 Writing Expressions and Equations.notebook
September 04, 2013
Today's Math Journal Questions
Day 1 Question: ______________________
(Date)
1. Why did you (or your parents) choose to take Double
Block Algebra this year?
2. What do you dislike about math? (“Everything” is not an acceptable answer)
3. What do you like about math? (“Nothing” is not an acceptable answer)
4. What grade(s) do you hope to earn this year in Double Block Algebra?
5. Is there anything special I can do to help make this class go as smoothly and least stressful as possible for you?
6. Circle when you have study hall this semester & list who your study hall teacher is
Day 1 Day 2 Block 1 Block 2 Block 3 Block 4
1st half of the block 2nd half of the block
Homework:
Worksheet 1-1
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