# RS Aggarwal Chapter 1 Class 9 Maths Exercises 1.2 (ex 1b) Solutions

RS Aggarwal Chapter 1 Class 9 Maths Exercise 1.2 Solutions : Number System is the essential study material for students preparing for the CBSE exam. “Number system” is the most important subject in mathematics because it also forms the basis for other chapters in mathematics. RS Aggarwal Maths Solutions Chapter 1 Class 9 has 7 exercises and has problems that give you complete information about numbers, such as numbers, ie real, natural, rational / irrational, imaginary, integer, prime and compound, respectively. Their representation on a number line, rationalization and exponential rules, etc.

Exercise 1b consists of 5 questions based on the concepts of rational numbers. There is a question where you have to find the number as a decimal.

Exercise 1B

## Important Definition for RS Aggarwal Chapter 11 Class 9 Maths Ex 1b Solutions

• Introduction to natural numbers-

The Set of positive counting numbers excluding zero are natural numbers.

• Whole numbers –

The Set of positive counting numbers including zero are whole numbers

• Integers –  Integers has two types-

Positive integers – Set of all natural numbers including zero is positive integers.

Negative integers – Set of all non-positive counting numbers including zero is negative integers.

• Rational Numbers-

Rational numbers are those types of numbers which are represented in the form of  (P/Q) where Q does not equal to zero

• How to find a rational number between two numbers

If  ‘a’ and ‘b’ are the two numbers-

Rational no.= (a+b)/2

• Irrational numbers –

A number that is not represented in the form of (P/Q) are irrational numbers.

• Real numbers –

Real numbers include all numbers which are rational or irrational.

• Prime numbers-

A number which is divided by number 1 and by itself are called prime numbers.

• Composite numbers- A composite number, is a positive integer or whole number that can be formed by the multiplication of two whole numbers.
• Complex numbers –

Complex numbers are those types of numbers that contain real as well as imaginary numbers.

• Laws of Exponent –

If a and b are the two numbers and m,n are the exponents –

1. am× an = am+n
2. (am)n= amn
3. ambm = (ab)m
4. a0= 1
5. a1= a
6. 1/an= a-n
• Rationalizing the denominator–

If the denominator contains a surd, then multiplying both by numerator and denominator by the surd is termed as rationalizing a denominator.

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