Question

find the value of 407x393 by suitable identity

Answer 1

Hi friend, Harish here.

Here is your answer:

407 × 393 can be written as: (400 + 7 ) ( 400 -7)..  

We know that,

(a+b)(a-b) = a² - b².

Here a = 400,  b = 7.

Then,

(400 + 7) ( 400 - 7) = (400)² - (7)²
 
                               = 1,60,000 - 49 
 
                               = 1,59,951

Therefore the answer is 1,59,951.
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Hope my answer is helpful to you.

Answer 2

407×394
we can write it as
(400+7)(400-7)
we know that (a+b)(a-b)= a^-b^ so
400^-7^=160000-49
=159951