## NCERT Solutions for Class 7 Maths Chapter 13 Exponents and Powers Ex 13.2

- Class 7 Maths Exponents and Powers Exercise 13.1
- Class 7 Maths Exponents and Powers Exercise 13.2
- Class 7 Maths Exponents and Powers Exercise 13.3

**NCERT Solutions for Class 7 Maths Chapter 13 Exponents and Powers Exercise 13.2**

Ex 13.2 Class 7 Maths Question 1.

Using laws of e×ponents, simplify and write the answer in e×ponential form:

(i) 3^{2} × 3^{4} × 3^{8}

(ii) 6^{15} ÷ 6^{10}

(iii) a^{3} × a^{2 }(iv) 7^{x} × 7^{2}

(v) (5^{2})^{3} ÷ 5^{3}

(vi) 2^{5} × 5^{5}

(vii) a^{4} × b^{4 }(viii) (3^{4})^{3}

(ix) (2^{20} ÷ 2^{15}) × 2^{3 }(x) 8^{t} ÷ 8^{2}

Solution:

(i) 3^{2} × 3^{4} × 3^{8} = 3^{2+4+8} = 3^{14} [a^{m} ÷ a^{n} = a^{m+n}]

(ii) 6^{15} ÷ 6^{10} = 6^{15-10} = 6^{5} [a^{m} ÷ a^{n} = a^{m-n}]

(iii) a^{3} × a^{2} = a^{3+2} = a^{5} [a^{m} × a^{n} = a^{m+n}]

(iv) 7^{x} × 7^{2} = 7^{x+2} [a^{m} × a^{n} = a^{m+n}]

(v) (5^{2})^{3} ÷ 5^{3} = 5^{2×3} ÷ 5^{3} = 5^{6} ÷ 5^{3} = 5^{6-3} = 5^{3} [(a^{3})^{n} = a^{mn}, a^{m} ÷ a^{n} = a^{m-n}]

(vi) 2^{5} × 5^{5} = (2 × 5)^{5} = 10^{5} [a^{m} × b^{m} = (ab)^{m}]

(vii) a^{4} × b^{4} = (ab)^{4} [a^{m} × b^{m} = (ab)^{4}]

(ix) (2^{20} ÷ 2^{15}) × 2^{3} = 2^{20-15} × 2^{3}

=2^{5} × 2^{3} = 2^{5+3} = 2^{8}

(x) 8^{t} ÷ 8^{2} = 8^{t-2} [a^{m} ÷ a^{n} = a^{m-n}]

Ex 13.2 Class 7 Maths Question 2.

Simplify and express each of the following in exponential form:

Solution:

Ex 13.2 Class 7 Maths Question 3.

Say true or false and justify your answer:

(i) 10 × 10^{11} = 100^{11}

(ii) 2^{3} > 5^{2}

(iii) 2^{3} × 3^{2} = 6^{5}

(iv) 3^{20} = (1000)^{0}

Solution:

(i) 10 × 10^{11} = 10^{1+11} = 10^{12}

RHS = 100^{11} = (10^{2})^{11} = 10^{22}

10^{12} ≠ 10^{22}

∴ Statement is false.

(ii) 2^{3} > 5^{2}

LHS = 2^{3} = 8

RHS = 5^{2}2 = 25

8 < 25

∴ 2^{3} < 5^{2}

Thus, the statement is false.

(iii) 2^{3} × 3^{2} = 6^{5}

LHS = 2^{3}3 × 3^{2} = 8 × 9 = 72

RHS = 6^{5} = 6 × 6 × 6 × 6 × 6 = 7776

∴ 72 ≠ 7776

∴ The statement is false.

(iv) 3^{0} = (1000)^{0}

⇒ 1 = 1 True [∵ a^{0} = 1]

Ex 13.2 Class 7 Maths Question 4.

Express each of the following as a product of prime factors only in exponential form:

(i) 108 × 192

(ii) 270

(iii) 729 × 64

(iv) 768

Solution:

(i) 108 × 192 = 2 × 2 × 3 × 3 × 3 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3

=2^{8} × 3^{4}

(iii) 729 × 64 = 3 × 3 × 3 × 3 × 3 × 3 × 2 × 2 × 2 × 2 × 2 × 2

=3^{6} × 2^{6}

Ex 13.2 Class 7 Maths Question 5.

Simplify:

Solution:

NCERT SolutionsMathsScienceSocialEnglishSanskritHindiRD Sharma

Subham Sinha says

It is very helpful. Thanx

MANASA says

it is very easy for me

MANASA says

it is helping very lot thanks

RAVI says

THANKS I LIKE IT VERY MUCH FOR YOUR HELP THANKS THANKS IT IS NICE

Aimann huda says

It helps me a lot I can understand all the exercise

Thanks a lotttt

VARUN KUMAR RANDHAWA says

THANK THIS BOOK SPECIAL THANKS SIR

Khushboo says

The content is very useful..

Thanks alot for providing the solutions!

pavithra says

good ……………………………………………

Munja says

Thanks its so much easy to understand math

Janani says

It is very easy to learn and understand the concept of whole chapter.. Thanxx

SARTHIK SPOLIA says

It is use

Keshav says

It is really very very helpful

Lekha says

I am just in love with this ……… It is sooooo damn helpful. I can write the examination very easily. I loooove it

alisha says

I got Very good website for Getting NCERT Maths CLass 7 Solutions, I will forward this site to all my friends they will feel happy with the resources.

Jaspreet says

What a aap it is very usefull for us thanks a lotttttttt

Aarzoo says

Really good helped me a lot in my homework and understanding the formulas

Thanks a lot

Chetan kankal says

Thanks for this answer .

This answer is very helpful .

Nihal Hadimani says

It’s very useful Thank you so much…..

Esha says

On

Mmm yes you are right

MHD sharmil says

IT is very useful and very nice app and Thanku so much