Question

Evaluate the following by using Identity l. i) (8.1)²

Answer 1

Answer:

$(8.1)^2=65.61$  

Step-by-step explanation:

Given : Expression $(8.1)^2$

To find : Evaluate the expression by using Identity?

Solution :

We can write the expression as

$(8.1)^2=(8+0.1)^2$

We know, The identity $(a+b)^2=a^2+b^2+2ab$

Substitute, a=8 and b=0.1

$(8+0.1)^2= {8}^{2} + {0.1}^{2} + 2(8)(0.1)$

$(8+0.1)^2= 64+1.6+ 0.01$

$(8+0.1)^2=65.61$

$\Righarrow (8.1)^2=65.61$

Therefore,  $(8.1)^2=65.61$

Answer 2

Given :  (8.1)²

Explanation:

Given that  (8.1)²

using the identity

(a+b)² = a²+b²+2ab

(8.1)² = (8+ 0.1)²

then

(8+ 0.1)²

here a = 8 and b = 0.1

thus

(8+ 0.1)²  = 8² + (0.1)² + 2(8) (0.1)

= 64 +1.6 + 0.01

= 65.61

hence , (8.1)² = 65.61