Question

using suitable identity valuate (i) 48^2 (ii) 97 × 103 (iii) 76^2 - 24^2 (iv) 64 × 69​

Answer 1

1) 48²

• ( 40 + 8 )²

using identity (a + b ) ²= a² + 2ab + b²

a= 40

b= 8

= (40)² + 2( 40 ) ( 8) + (8)²

= 1600 + 640 + 64

= 2304

2) 97 × 103

• ( 100 + 3 ) ( 100 - 3 )

using identity (a+b) (a-b ) = a²- b²

a= 100

b = 3

= (100)²- (3)²

= 10000 - 9

= 9991

3) 76²- 24²

• using identity a²-b²= (a+b) (a-b)

a= 76

b= 24

= (76 - 24 ) (76 + 24 )

= ( 52 ) (100)

= 5200

hope it helps you..