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Variables
and
Expressions |
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Key
Idea
Variables can be
used to write
algebraic
expressions that
describe realworld
situations. |
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| What
is an algebraic expression? |
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Monique wants to buy
tickets to a basketball game
for herself and some friends. Write an algebraic
expression to represent the total cost of the tickets. |
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Vocabulary
• variable
• algebraic
expression |
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In the chart below, n
represents the number of
tickets that Monique buys. The total cost of the
tickets can be represented by $5.50 x
n. |
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We call n
a variable because
it stands for a value that
can change or vary. $5.50 x n
is called an algebraic
expression.
An algebraic expression is a mathematical
phrase involving variables, numbers, and
operations.
Other examples of algebraic expressions are shown below. |
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 | Addition |
Subtraction |
Multiplication |
Division |
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| 4
+ a,
or a
+ 4 |
b
– 4 |
4 x c,
or 4c |
| d
÷ 4, or |
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Talk About It |
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| 1. |
Why was
a variable used to represent the number
of tickets Monique buys? |
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| 2. |
If each
ticket cost $6.75 instead of $5.50, what
expression could you use to represent the total
cost of the tickets? |
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| 3. |
Explain
the meaning of the algebraic expression
$5.50n. |
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