Let the two numbers are x and y Then S1:xy=21‌‌‌‌‌⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅(i) S2:x+y=10‌‌‌‌‌⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅(ii) ∴(x−y)2=(x+y)2−4xy ‌‌=(10)2−4×21 ‌‌=100−84 ‌‌=16=42 ⇒(x−y)2=42 ⇒x−y=4‌‌‌‌‌⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅(iii) Adding (ii) and (iii), we get,From (i) 2x=14⇒x=7 y=‌