Download Study Guide and Intervention Variables and Expressions

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Study Guide and Intervention
Variables and Expressions
Write Mathematical Expressions In the algebraic expression, Eio , the letters €
and ware called variables. In algebra, a variable is used to represent unspecified numbers
or values. Any letter can be used as a variable. The letters € and ware used above because
they are the first letters ofthe words length and width. In the expression Eio , € and ware
called factors, and the result is called the product.
Write an algebraic expression for each verbal expression.
a. four more than a number n
The words more than imply addition.
four more than a number n
4 +n
The algebraic expression is 4 + n.
b. the difference of a number squared and 8
The expression difference o{implies subtraction.
the difference of a number squared and 8
n 2 - 8
The algebraic expression is n 2 - 8.
Evaluate each expression.
b. five cubed
a. 3 4
Cubed means raised to the third power.
3 4 = 3 . 3 . 3 . 3 Use 3 as a factor 4 times.
Multiply.
= 81
53 = 5 . 5 . 5
Use 5 as a facto' 3 . ~es
=
125
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Study Guide and Intervention
(continued)
Variables and Expressions
Write Verbal Expressions Translating algebraic expressions into verbal expressions
is important in algebra.
Write a verbal expression for each algebraic expression.
a. 6n 2
the product of 6 and n squared
b. n 3
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12m
the difference of n cubed and twelve times m
Glencoe Algebra 1
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Practice
Variables and Expressions
Write an algebraic expression for each verbal expression.
1. the difference of 10 and u
2. the sum of 18 and a number
3. the product of 33 and}
4. 74 increased by 3 times y
5. 15 decreased by twice a number
6.91 more than the square of a number
7. three fourths the square of b
8. two fifths the cube of a number
Evaluate each expression.
9. 11 2
13.9 3
17. 100 4
15. 105
Write a verbal expression for each algebraic expression.
18.23f
19.7 3
20. 5m 2
+ 2
21. 4d 3
25.
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10
4;2
26. BOOKS A used bookstore sells paperback fiction books in excellent condition for
$2.50 and in fair condition for $0.50. Write an expression for the cost of buying e
excellent-condition paperbacks and f fair-condition paperbacks.
27. GEOMETRY The surface area ofthe side of a right cylinder can be found by multiplying
twice the number 7T by the radius times the height. If a circular cylinder has radius r
and height h, write an expression that represents the surface area of its side.
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Glencoe/McGraw-Hili
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Glencoe Algebra 1