1. Algebra Introduction

2. You are familiar with the following type of numerical expressions:
3 (12)
6 ( )
(6)

3. Algebraic Expressions
When variables are used with other numbers, brackets, or operations, they create an algebraic expression.
a + 2
(a) (b)
3m + 6n - 6
4m2n + 7mn - 6

4. What is a variable?
A variable is an alphabet that represents an unknown value. b
Few more examples:
Expression
Constants
Variable
Algebraic expressions
Variable
13mn-7 mn
2x2-4x+9
x2,x
12k2x-3k-8
k2x, k

5. What are constants? 5x +7y -2
A constant is a number that cannot change its value.
Expression
5x +7y -2
5, , are the Constants
Few more examples:
Algebraic expressions
Constants
Variable
13mn-7 mn
13 , - 7
2x2-4x + 9
2,-4 , 9
x2,x
12k2x-3k-8
12 , -3, -8
k2x , x

6. What is a term?
A term is a constant or a variable or a product of constant and one or more variables.
Expressions a
Term 1
Term 2
Algebraic expressions
Term
3m + 6n -6
3m, 6n,-6
4m2n, 7mn , -5
4m2n + 7mn - 5

7. Example 1: Identify the constants and variables from the following
xy , y , 4 , 1/3 , z
Solution
Term xy , y and z contains variable
Term 4 and 1/3 has only constants
Therefore
Constants = 4 , 1/3
Variables = xy , y , z (ans)

8. Example 2: Identify the constants and variables from the following
x2y , 2/3 , -x/5 , 62 , 9x
Solution
Term x2y , -x/5 and 9x contains variable
Term 2/3 and 62 has only constants
Therefore
Constants = 2/3 , 62
Variables = x2y , -x/5 , 9x (ans)

9. Try These Identify the constants and variables from the following
-5p , -3 , -2/x , -6/5
b) , x 2, 3x , -6