Q3 of 31 Page 102

Find the square roots of 100 and 169 by the method of repeated subtraction

The square root of 100 can be obtained by the method of repeated subtraction as:

(i) 100 - 1 = 99 (ii) 99 - 3 = 96 (iii) 96 - 5 = 91


(iv) 91 - 7 = 84 (v) 84 - 9 = 75 (vi) 75 - 11= 64


(vii) 64 - 13 = 51 (viii) 51 - 15 = 36 (ix) 36 - 17 = 19


(x) 19 - 19 = 0


In this we have subtracted successive odd numbers starting from 1 to 100, and obtained 0 at 10th step


Therefore,



The square root of 169 can be obtained by the method of repeated subtraction as:


(i) 169 - 1 = 168 (ii) 168 - 3 = 165 (iii) 165 - 5 = 160


(iv) 160 - 7 = 153 (v) 153 - 9 = 144 (vi) 144 - 11 = 133


(vii) 133 - 13 = 120 (viii) 120 - 15 = 105 (ix) 105 - 17 = 88


(x) 88 - 19 = 69 (xi) 69 - 21 = 48 (xii) 48 - 23 = 25


(xiii)25 - 25 = 0


We have subtracted successive odd numbers starting from 1 to 169, and obtained 0 at 13th step


Hence,



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