Question

using suitable identity find
1. (10.8)
2. (997)²​

Answer 1

Answer:

Answer

Using (a+b)

2

=a

2

+2ab+b

2

We can write (10.2)

2

=(10+0.2)

2

= (10)

2

+2(10)(0.2)+(0.2)

2

= 100+4+0.04

Hence the answer is 104.04

verified_toppr

Answer 2

1). (997)2

= (1000−3) 2

= (1000) 2 −2×1000×3+(3) 2

= (1000) 2 −2×1000×3+(3) 2 [Using, (a−b) 2 =a2 −2ab+b2]

= (1000) 2 −2×1000×3+(3) 2 [Using, (a−b) 2 =a2 −2ab+b2] = 1000000−6000+9

= (1000) 2 −2×1000×3+(3) 2 [Using, (a−b) 2 =a2 −2ab+b2] = 1000000−6000+9 = 1000009−6000

= (1000) 2 −2×1000×3+(3) 2 [Using, (a−b) 2 =a2 −2ab+b2] = 1000000−6000+9 = 1000009−6000= 994009 ans :-