Class 8 Maths Chapter 12 Exponents and Powers

Exercise 12.1

Question 1.
Evaluate:
(i) 3-2
(ii) (-4)-2
(iii) (1/2)-5
Solution:

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

Solution:

Question 3.
Find the value of

Solution:

Question 4.

Solution:

Question 5.
Find the value of m for which 5m ÷ 5-3 = 55.
Solution:
5m ÷ 5-3 = 55
⇒ 5m-(-3) = 55 [∵ am ÷ an = am-n]
⇒ 5m+3 = 55
Comparing the powers of equal bases, we have
m + 3 = 5
m = 5 – 3 = 2, i.e., m = 2

Question 6.
Evaluate:

Solution:

Question 7.
Simplify:

Solution:

Exercise 12.2

 

 

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