1. SECTION 1-1 : VARIABLES and EXPRESSIONS
ALGEBRA I @
SECTION 1-1 : VARIABLES and EXPRESSIONS

2. At the end of this lesson you should be able to write an algebraic expression using symbols and operations.

3. NUMERICAL EXPRESSION : A statement that contains only numbers and mathematical operations (6 + 2 ÷ 4).
More examples :
VARIABLE : A symbol that stands for a number.
For x – 5 = 8, what is the variable?
ANSWER : x
ALGEBRAIC EXPRESSION : A statement that contains numbers, variables, and mathematical operations (45n,
3x – 5).
More examples :

4. EQUATION : A sentence that contains an equals sign (5x + 3 = 12).
More examples :
ADDITION
plus
more than
the sum of
increased by
added to
the total of
in all
gain
SUBTRACTION
minus
less than**
the difference of
decreased by
subtracted from**
fewer than**
descend
deflate

5. MULTIPLICATION
the product of
multiplied by
times
twice/thrice of
powers
area/volume
double/triple
DIVISION
the quotient of
divided by
the ratio of
half
per
goes into
out of
EXPONENTS
squared
cubed
to the _____ power

6. Write an algebraic expression for each word phrase.
1) x minus five
ANSWER : x - 5
2) x less than five
ANSWER : 5 - x
3) y cubed
ANSWER : y3
4) half of x increased by eight
ANSWER : (1/2)x + 8
5) the quotient of y and seven
ANSWER : y ÷ 7

7. Write a word phrase for each algebraic expression.
6) 5m6
Possible Answer : The product of five and m to the sixth power. 7)
Possible Answer : The product of one-third and x squared.

8. 8) 4x – 5x2
Possible Answer : The difference of the product of four and x and the product of five and x squared.
9) y2 + 17
Possible Answer : The sum of y squared and seventeen.

9. Possible Answer : 3g – 7 = 31 Write an equation for each sentence.
10) The quotient of t and eight is equal to twenty.
Possible Answer :
t ÷ 8 = 20
11) Seven less than the product of
three and g is thirty-one
Possible Answer : 3g – 7 = 31

10. ALGEBRA I - SECTION 1-1 (Variables and Expressions)
Write a sentence for each equation.
12) j + 4 = 21
Possible Answer : The sum of j and four is equal to twenty-one.
13) 3z – 12 = 15
Possible Answer : The product of three and z decreased by twelve is equal to fifteen.