The identity used in simplifying 103 x 97 A) (a + b)2 = a2 + 2ab + b2

1.	The identity used in simplifying 103 x 97 A) (a + b)2 = a2 + 2ab + b2 B) (a – b)2 = a2 – 2ab + b2 C) (a – b) (a + b) = a2 – b2 D) (x + a) (x + b) = x2 + (a + b) x + ab
Answer» Correct option is (C) (a – b) (a + b) = a² – b² \(103\times97\) = (100 + 3) (100 - 3) Let a = 100, b = 3 Then \(103\times97\) \(=(a+b)(a-b)\) \(=a^2-b^2\) \(=100^2-3^2\) = 10000 - 9 = 9991 \(\therefore\) Identity that is used in simplifying \(103\times97\) is \((a-b)(a+b)=a^2-b^2.\) C) (a – b) (a + b) = a² – b²

The identity used in simplifying 103 x 97 A) (a + b)2 = a2 + 2ab + b2 B) (a – b)2 = a2 – 2ab + b2 C) (a – b) (a + b) = a2 – b2 D) (x + a) (x + b) = x2 + (a + b) x + ab

Answer»

Correct option is (C) (a – b) (a + b) = a² – b²

\(103\times97\) = (100 + 3) (100 - 3)

Let a = 100, b = 3

Then \(103\times97\) \(=(a+b)(a-b)\) \(=a^2-b^2\)

\(=100^2-3^2\)

= 10000 - 9 = 9991

\(\therefore\) Identity that is used in simplifying \(103\times97\) is \((a-b)(a+b)=a^2-b^2.\)

C) (a – b) (a + b) = a² – b²