ALGEBRA

3.1       ALGEBRAIC EXPRESSION

An algebraic expression is a combination of numbers, alphabets, and operational symbols.

For example

	(i)    x – 3  (ii)  -4x2 + 5x + 7    (iii)   xy – x + 5

The ‘+’ and ‘–‘ signs in algebraic expressions break up the expression into small parts called terms.

For example :

           

Expression	Term	No of Terms
x – 3	x, 3	2
-4x2 + 5x + 7	-4x2, 5x, 7	3
+ 1	, 1	2
xy – x + 5	xy, x, 5	3
		1

The numerical part of a term is called its coefficient. It can be positive or negative.

The alphabetical part of a term is called the unknown. It is a quantity of which the value is not yet known. A term with one unknown has one alphabet, two unknowns has two alphabets and three unknowns has three alphabets in it.

In Algebra, a constant is a number on its own or sometimes a letter such as a, b, or c to stand for a fixed number.  

Let, example as shows below:

For example :

                                                          

Term	Coefficient	Unknown	Constant
5x - 3	5	x	-3
-4x²	-4	x²	0

Terms with same unknowns are called like terms and terms with different unknowns are unlike terms.

For example :

Expression	Like Term	Unlike Term
x – 3 + 5x	x and 5x	x and 3 5x and 3
-4x2 + 5x + 2x2 – 3x	-4x2 and 2x2 5x and -3x	-4x2 and 5x -4x2 and 3x 5x and 2x2 2x2 and 3x