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Number System Class 9 Chapter 1 Ex 1.5 NCERT Solutions

Number System Class 9 Exercise 1.5 deals with rational exponents and their applications. Get step-by-step NCERT solutions and explanations to practise efficiently.
authorImageAnshika Agarwal19 Nov, 2025
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NCERT Solutions Class 9 Chapter 1 Ex 1.5

Number System Class 9 Exercise 1.5 Chapter 1 extends the application of exponent rules to more complex problems. It reinforces concepts of rational exponents and shows how to apply them in expressions. 

NCERT Maths Class 9 Number System Exercise 1.5 solutions provide clear and  step-by-step solutions to solve problems easily. They include worked examples that explain how to handle rational exponents, simplify expressions, and avoid common errors. 

Class 9 Chapter 1 Number System Exercise 1.5 Questions

Class 9 Chapter 1 Number System Exercise 1.5 Questions focus on applying rational exponents to real numbers. Practising these questions with clear solutions helps develop speed and accuracy. NCERT questions along with step by step solutions are given here:

1. Find:

(i)64 1/2

Solution: 64 1/2 = (8×8) 1/2 = (8 2 ) ½ = 8 1 [⸪2×1/2 = 2/2 =1] = 8

(ii)32 1/5

Solution: 32 1/5 = (2 5 ) 1/5 = (2 5 ) ⅕ = 2 1 [⸪5×1/5 = 1] = 2

(iii)125 1/3

Solution: (125) 1/3 = (5×5×5) 1/3 = (5 3 ) ⅓ = 5 1 (3×1/3 = 3/3 = 1) = 5

2. Find:

(i) 9 3/2

Solution: 9 3/2 = (3×3) 3/2 = (3 2 ) 3/2 = 3 3 [⸪2×3/2 = 3] =27

(ii) 32 2/5

Solution: 32 2/5 = (2×2×2×2×2) 2/5 = (2 5 ) 2⁄5 = 2 2 [⸪5×2/5= 2] = 4

(iii)16 3/4

Solution: 16 3/4 = (2×2×2×2) 3/4 = (2 4 ) 3⁄4 = 2 3 [⸪4×3/4 = 3] = 8

(iv) 125 -1/3

Solution: 125 -1/3 = (5×5×5) -1/3 = (5 3 ) -1⁄3 = 5 -1 [⸪3×-1/3 = -1] = 1/5

3. Simplify :

(i) 2 2/3 ×2 1/5

Solution: 2 2/3 ×2 1/5 = 2 (2/3)+(1/5) [⸪Since, a m ×a n =a m+n ____ Laws of exponents] = 2 13/15 [⸪2/3 + 1/5 = (2×5+3×1)/(3×5) = 13/15]

(ii) (1/3 3 ) 7

Solution: (1/3 3 ) 7 = (3 -3 ) 7 [⸪Since,(a m ) n = a m x n ____ Laws of exponents] = 3 -21

(iii) 11 1/2 /11 1/4

Solution: 11 1/2 /11 1/4 = 11 (1/2)-(1/4) = 11 1/4 [⸪(1/2) – (1/4) = (1×4-2×1)/(2×4) = 4-2)/8 = 2/8 = ¼ ]

(iv) 7 1/2 ×8 1/2

Solution: 7 1/2 ×8 1/2 = (7×8) 1/2 [⸪Since, (a m ×b m = (a×b) m ____ Laws of exponents] = 56 1/2

NCERT Maths Class 9 Number System Exercise 1.5 PDF

NCERT solutions for class 9 Maths Number System Exercise 1.5 PDF includes step-by-step solutions. This makes it easier for students to revise rational exponent problems anytime. The PDF also explains simplified expressions to help students prepare effectively.

By regularly using this resource, you can improve your understanding of Number System Class 9 concepts and confidently handle questions related to rational exponent questions in the exam.

NCERT Maths Class 9 Number System Exercise 1.1 PDF

Number System ONE SHOT Full Chapter Class 9th Maths Youtube Video

 

NCERT Solutions Class 9 Chapter 1 Ex 1.5 FAQs

What is a rational exponent in Class 9?

A rational exponent represents roots and powers simultaneously, like x^(m/n) = n√(x^m).

How do I simplify expressions with rational exponents?

Apply the exponent rules carefully, convert fractional powers to roots, and then simplify step by step.

Are rational exponent questions important for exams?

Yes, they are commonly tested and form a key part of the number system chapter.

Is there a PDF available for NCERT Solutions Class 9 Chapter 1 Ex 1.5?

Yes, a downloadable NCERT Solutions Class 9 Chapter 1 Ex 1.5 PDF is available. It includes all solved questions.

How can I avoid mistakes in rational exponent problems?

Always convert fractional exponents to root form if needed and simplify gradually.
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