EVENTS CONVENT HIGH SCHOOL
27/01/2022 CLASS- 7 SESSION 2021-22
SUBJECT : MATHS
CHAPTER-13 (EXERCISE13.2)
EXPONENTS AND POWERS
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Question 1.Using laws of e×ponents, simplify and write the answer in e×ponential form:
(i) 32 × 34 × 38
(ii) 615 ÷ 610
(iii) a3 × a2
(iv) 7x × 72
(v) (52)3 ÷ 53
(vi) 25 × 55
Solution:
(i) 32 × 34 × 38 = 32+4+8 = 314 [am ÷ an = am+n]
(ii) 615 ÷ 610 = 615-10 = 65 [am ÷ an = am-n]
(iii) a3 × a2 = a3+2 = a5 [am × an = am+n]
(iv) 7x × 72 = 7x+2 [am × an = am+n]
(v) (52)3 ÷ 53 = 52×3 ÷ 53 = 56 ÷ 53 = 56-3 = 53 [(a3)n = amn, am ÷ an = am-n]
(vi) 25 × 55 = (2 × 5)5 = 105 [am × bm = (ab)m]
Question 2.Simplify and express each of the following in exponential form:
Solution:
