Exercise 16.2
1) Compute the following, Give the answer in
the exponential form,
(i) 2x2
(ii) (-3)" x (-3)
3
(iv)
w) 65")*61)
X
4
4
(vi) (-3)+(-3)
(v) 3+3
3
2.
(vii)
2 5
(viii)
5
(ix) 3 + 3%
(x) (-3)+(-3)
2
2
() (f) - €)
1
(xii)
5
4
Answers
Answer:swer:
(i) 26 = 2 * 2 * 2 * 2 * 2 * 2 = 64
(ii) 93 = 9 * 9 * 9 = 729
(iii) 112 = 11 * 11 = 121
(iv) 54 = 5 * 5 * 5 * 5 = 625
Question 2:
Express the following in exponential form:
(i) 6 * 6 * 6 * 6 (ii) t * t (iii) b * b * b * b (iv) 5 * 5 * 7 * 7 * 7 (v) 2 * 2 * a * a
(vi) a * a * a * c * c * c * c * d
Answer:
(i) 6 * 6 * 6 * 6 = 64
(ii) t * t = t2
(iii) b * b * b * b = b4
(iv) 5 * 5 * 7 * 7 * 7 = 52 * 73
(v) 2 * 2 * a * a = 22 * a2
(vi) a * a * a * c * c * c * c * d = a3 * c4 * d
Question 3:
Express each of the following numbers using exponential notations:
(i) 512 (ii) 343 (iii) 729 (iv) 3125
Answer:
(i) 512 = 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 29
Class_7_Exponents_&_Powers_Primefactorization_of_512
(ii) 343 = 7 * 7 * 7 = 73
Class_7_Exponents_&_Powers_Primefactorization_of_343
(iii) 729 = 3 * 3 * 3 * 3 * 3 * 3 = 36
Class_7_Exponents_&_Powers_Primefactorization_of_729
(iv) 3125 = 5 * 5 * 5 * 5 * 5 = 55
Class_7_Exponents_&_Powers_Primefactorization_of_3125
Question 4:
Identify the greater number, wherever possible, in each of the following:
(i) 43 and 34 (ii) 53 or 35 (iii) 28 or 82 (iv) 1002 or 2100 (v) 210 or 102
Answer:
(i) 43 = 4 * 4 * 4 = 64
34 = 3 * 3 * 3 * 3 = 81
Since 64 < 81
So, 34 is greater than 43
(ii) 53 = 5 * 5 * 5 = 125
35 = 3 * 3 * 3 * 3 * 3 = 243
Since 125 < 243
So, 35 is greater than 53
(iii) 28 = 2 * 2 * 2 * 2 * 2 * 2 * 2 * 2 = 256
82 = 8 * 8 = 64
Since, 256 > 64
Thus, 28 is greater than 82
(iv) 1002 = 100 * 100 = 10,000
2100 = 2 * 2 * 2 * 2 * 2 * …..14 times * ……… * 2 = 16,384 * ….. * 2
Since, 10,000 < 16,384 * ……. * 2
Explanation: