# Class 8 Maths Chapter 1 Exercise 1.1 Pdf Notes NCERT Solutions

Class 8 Maths Chapter 1 Rational Number exercise 1.1 pdf notes:-

**Exercise 1.1** Class 8 maths Chapter 1 Pdf Notes:-

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## Ncert Solution for Class 8 Maths Chapter 1 Rational Number Exercise 1.1 Tips:

**Introduction:-**

In Mathematics, we frequently come across simple equations to be solved. For example,

the equation x + 2 = 13

is solved when x = 11, because this value of x satisfies the given equation. The solution

11 is a natural number. On the other hand, for the equation

x + 5 = 5

the solution gives the whole number 0 (zero). If we consider only natural numbers,

equation cannot be solved. To solve equations like , we added the number zero to

the collection of natural numbers and obtained the whole numbers. Even whole numbers

will not be sufficient to solve equations of type

x + 18 = 5

Do you see ‘why’? We require the number –13 which is not a whole number. This

led us to think of integers, (positive and negative). Note that the positive integers

correspond to natural numbers. One may think that we have enough numbers to solve all

simple equations with the available list of integers. Now consider the equations

2x = 3

5x + 7 = 0

What We Have Discussed

- Rational numbers are closed under the operations of addition, subtraction and multiplication
- The operations addition and multiplication are (i) commutative for rational numbers. (ii) associative for rational numbers.
- The rational number 0 is the additive identity for rational numbers.
- The rational number 1 is the multiplicative identity for rational numbers.
- Distributivity of rational numbers: For all rational numbers a, b and c, a(b + c) = ab + ac and a(b – c) = ab – ac
- Rational numbers can be represented on a number line
- Between any two given rational numbers there are countless rational number. the idea of mean helps us to find rational number between any two rational numbers.