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Contents
Simple Algebraic Expressions
Factorisation of Quadratic Polynomials
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Algebraic
Expressions
It is the use of symbols to replace numbers.
Suppose you are 13 years old now. After 1 year, you will be (13+1) years old. After 2 years, you will be (13+2) years old. After 3 years, you will be (13+3) years old. After x years, you will be (13+x) years old.
Example 1:  John is three
times as tall as Paul. If Paul is s m tall, what is John's height?
 3 x s = 3s m tall
His height is 3s m.
Example 2:
What is the total value of h $0.50 coins and j $10 notes in dollars?
0.5 x h + 2 x
k = $(0.5h+2k)
The value is $(0.5+2k)
Example 3:
Jane is y years
old. What is the present age of Jane's aunt if her aunt is four times as old as
Jane will be 2 years from now?
2 years from
now, Jane will be (y +2) years old.
4 x (y+2) = 4(y+2)
The aunt will be 4(y+2) years old.
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Note: Here, x may represent any number. The
expression (13+x) years old represents your age in x
years time. x is called a variable.
