So far you have been learning with numbers that have definite values. You have learnt how to add, subtract, multiply and divide numbers. Working with numbers called Arithmetic
In English, we say phrases has no definite meaning. Similarly, ‘expressions’ in mathematics have no definite meaning.
Let us take an example
| Verbal | Numerical |
|---|---|
| Phrases | Expression |
| I drink Five added to 6 | 3+4 5+6 |
Statements have definite meaning. So, the equation has definite meaning
Statement | Equation |
|---|---|
| Three added to four is seven Number x decreased by 4 is 25 | 3+4=7 is a Numerical equation x – 4 = 25 Algebraic Equation |
You have already learnt Area of rectangle = length x width
A = Area, l= length, w= width
Length = 4cm, width = 3cm then Area = 4 * 3 = 12 sq. cm
Here alphabet ‘l’ represents 4 and ‘w’ represents 3. So, Letter represents numbers. A= l x w is a Literal equation.
What is the perimeter of a square?
Perimeter = 4 * side length
P= 4 * s where s is the side length
In this equation, we have numbers, alphabets and mathematical operation Multiplication. It is an Algebraic equation.
Alphabets or letters represent different numbers, so they are called Variables. Numbers are called constants
A quantity which has a fixed numerical value is called a constant. Example
Numbers.
A quantity which can be take various numerical values is called a variable, Alphabets,
| A quantity which has a fixed numerical value is called a constant. A quantity which can be take various numerical values is called a variable |
An algebraic expression is a combination of numbers and variable joined by the signs of fundamental operations ( +, -, x, and ÷ )
Two algebraic expressions joined together with an equal to sign(=) is called algebraic equation.