Question

Find the square roots of 121 and 169 by the method of repeated subtraction.

Answer 1

(i) 121 121-1 = 120
120-3 = 117
117-5=112
112-7 = 105
105-9= 96
96-11= 85
85-13 = 72
72-15=57
57-17= 40
40-19 = 21
21-21=0
$\therefore Squareroot=11$

(ii) 169 169-1 = 168
168-3 = 165
165-5 = 160
160-7 = 153
153-9 = 144
144-11= 133
133-13 = 120
120-15 = 105
105-17 = 88
88-19 = 69
69-21 = 48
48-23 = 25
25-25 = 0
$\therefore$Square root = 13