Question

evaluate, using suitable identity: 1) 2.07*1.93​

Answer 1

Answer:

3.9951

Step-by-step explanation:

(2 + 0.07)(2 - 0.07)

= (2^2) - (0.07^2)

= 4 - (49 × 0.0001)

= 4 - 0.0049

= 3.9951

Answer 2

$2.07\times 1.93=3.9951$

Concept :

Let us know an algebraic identity before we solve the problem. If $a$ and $b$ be two numbers such that $a>b$, then we have the following identity:

$\quad a^{2}-b^{2}=(a+b)(a-b)$

Step-by-step explanation:

We write:

• $2.07=2+0.07$
• $1.93=2-0.07$

So, $2.07\times 1.93$

$=(2+0.07)\times (2-0.07)$

• Now we apply the identity written in the Concept part of this answer.

$=(2)^{2}-(0.07)^{2}$

$=4-0.0049$

$=3.9951$