Mathematics – Class 8 – Chapter 12 -Exponents and Powers- Exercise 12.1 – NCERT Exercise Solution

1. Evaluate:

(i) 3-2 (ii) (-4)-2 (iii) (1/2)-5 

Solution:

(i) 3-2 = (1/3)2

[a-m = 1/am]

= 1/9

(ii) (-4)-2 = (1/-4)2

[a-m = 1/am]

= 1/16

(iii) (1/2)-5 = (2/1)5

[a-m = 1/am]

= 25

= 32

2. Simplify and express the result in power notation with positive exponent:

(i)(-4)5 ÷(-4)8  

Solution:

= [ am / an = am-n]

= (-4)5-8

= 1/43

(ii) (1/23)2 

Solution:

= 12/ (23)2

= 1/26

(iii) (-3)4× (5/3)4

Solution:

= (-3)4 × (54/34)

= 54

(iv) (3-7÷3-10) ×3-5 

Solution:

= 3-7 – 10 × 3-5 

= 33   × 3-5 

= 3-2

= 1/32   

(v) 2-3 × (-7)-3

Solution:

= [2× (-7)]-3

= (-14)-3

= -(1/143)

3. Find the value of:

(i)(30+4-1)×22

Solution:

= (1+(1/4)) ×22

= ((4+1)/4) ×22

= (5/4) ×4

= 5

(ii) (2-1×4-1) ÷2 – 2

Solution:

= [(1/2)×(1/4)] ÷(1/4)

= (1/2×1/22) ÷ 1/4

= 1/23 ÷ 1/4

= (1/8) × (4)

= 1/2

(iii) (1/2)-2+(1/3)-2+(1/4)-2

Solution:

= (2-1)-2+(3-1)-2+(4-1)-2

= 2(-1×-2) + 3(-1×-2) + 4(-1×-2)

= 22+32+42

= 4+9+16

=29

(iv) (3-1+4-1+5-1)0

Solution:

= 1

(v) {(-2/3)-2}2

Solution:

= (-2/3)-2×2

= (-2/3)-4

= (-3/2)4

= 81/16

4. Evaluate

(i)(8-1×53)/2-4

(ii) (5-1×2-2) × 6-1

Solution:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

5. Find the value of m for which 5m ÷ 5-3 = 55

Solution:

Given, 5m ÷ 5-3 = 55

5m-(-3) = 55 [am ÷ an = am-n]

5 m+3 = 55

Comparing the powers of equal bases

m + 3 = 5

m = 5 – 3 = 2

m = 2

6.Evaluate:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

Solution:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution
Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

Solution:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

7. Simplify:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

Solution:

Given:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution
Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

Solution:

Mathematics - Class 8 - Chapter 12 -Exponents and Powers- Exercise 12.1 - NCERT Exercise Solution

👍👍👍

About the Author: MakeToss

Leave a Reply

Your email address will not be published. Required fields are marked *

Ads Blocker Image Powered by Code Help Pro

Ads Blocker Detected!!!

We have detected that you are using extensions to block ads. Please support us by disabling these ads blocker.

error: